Quiz 3 content

sigma factors in prokaryotic RNA polymerase help recognize certain consensus sequences. What are the major and minor bacterial factors?

major: TTGACA and TATAAT minor: CTTGAA and CCCGATAT at -27, CTGG; -10 is TTGCA these ones are minor because they are when E.coli are under special conditions look at image. by changing sigma regulation can change gene expression!

only tRNA ____ uses anticodon solely for recognition; most synthetases use both overall tRNA structure as well as the anticodon for recognition

met

the ______ site of synthetases allows the formation of correct aminoacyl-tRNA whereas the _____ site destroys incorrectly formed Aminoacyl-AMP-enzyme intermediates. The proof reading assures high fidelity (mistake rate is 1/1000)

synthetic hydrolytic in image, if tRNA-IIe binds to valine, not isoleucine, then hydrolytic domain is activated and the binding is no accomplished (confused about the image seems other way around)

for RNA transcription initiation in prokaryotes, the prokaryotic promoter contains what two essential regions?

the -35 region and the -10 region or Pribnow box. The negative just means bases that are upstream from the transcribed bases. Already transcribed bases are positive. Sequence of the non-template strand are given. These sequences are called the consensus sequence (a sequence of DNA having similar structure and function in different organisms) . These two regions are found in genes that are actively transcribed.

what is the purpose of capping in RNA processing?

the cap is required for export of the message to the cytoplasm, enhances efficiency of splicing and translation, and stabilizes mRNA

how does tRNA act as an adaptor?

the codon determines the amino acid and the tRNA acts as an adapter between the amino acid and the codon the main acid doesn't recognize the mRNA - that is the job of the tRNA

what is translation?

the decoding of an mRNA message into a protein

T/F: RNA splicing is of broad occurrence in different eukaryotes.

true

T/F: mRNA processing occurs during transcriptional elongation

true

T/F: the unusual bases in tRNA are the result of the modification in the precursor molecule

true ex. with yeast tyrosine tRNA, there is cleavage at the 5' end and terminal addition at the 3' end. In addition, there is a removal of an intervening sequence and modification of bases.

T/F: alternate splicing can cause diversity by making different proteins out of the same gene

true in the image, a tropomyosin gene can make a different protein in smooth muscle, striated, etc. due to alternate splicing.

T/F: the ribosome is a ribozyme?

true rRNAs form the catalytic site of protein synthesis

T/F: RNA processing is unique to eukaryotes?

true!

protein production is completed by ribosomes made of how many subunits? what are they for prokaryotes vs. eukaryotes?

two prokaryotes: 30s and 50s form 70s eukaryotes: 40s and 60s form 80s

what is trans splicing?

two different RNA molecules can be spliced together

rRNA processing process in eukaryotes.

unsure what this slide means

structure of eukaryotic vs. prokaryotic RNA polymerases?

unsure which structure is which. ask

in eukaryotic RNA transcription, is TATA box upstream or downstream of RNA polymerase II?

upstream

Watson-Crick base pairing vs. wobble base pairing: ____ pairs with GAG?

watson-crick: CUC wobble: CUU CUU is imperfect pairing.

elongation in prokaryotes: step 1 tRNA binding

- Aminoacyl-tRNA binds to GTP-EF Tu - The binding of aminoacyl-tRNA to A site on ribosome couples with the hydrolysis of GTP to GDP and Pi - EF Ts replaces GDP and binds to EF Tu GTP replaces EF Ts and binds to EF Tu - The replenishment of GTP-EF Tu is accomplished - In eukaryotes, similar reaction is catalyzed by eEF1ɑ and eEF1β in place of Tu and Ts, respectively

translation inhibitor: puromycin

- Analog of the 3' aminoacyl-adenosine part of the tRNA (CCA), binding to A site of ribosome - The amino group on puromycin form peptide bond with the carboxyl group of the polypeptide chain. - Elongation is inhibited and polypeptide- puromycin is released. - Inhibits both prokaryotes and eukaryotes

How does initiation of RNA transcription occur in prokaryotes?

- DNA sequence information signals RNA synthesis" - RNA polymerase specifically binds to DNA region upstream of the gene which is termed the promoter

elongation in prokaryotes step 3: translocation

- EF-G, the translocase, binds to GTP. - The hydrolysis of GTP drives the ribosome to move 1 codon toward the 3' direction of the mRNA. - The dipeptidyl-tRNA is now at P site, while the uncharged tRNA at E site and released to the cytosol - The A site is now open to accept new aminoacyl-tRNA -In eukaryotes, the translocase eEF2 works in similar fashion as EF-G

What experiment told us that tRNA is the only adapter in translation?

- Raney Nickel experiment - Raney Nickel removes sulfur from Cysteine, creating Alanine - Alanine is incorporated at codons for cysteine - tRNAs deliver amino acid to the translational machinery ask about this in OH

termination of translation in eukaryotes

- Termination codons: UAA, UAG, UGA - RF-1 or RF-2 (release factor) recognizes and bind to termination codons at A site - Promotes the peptidyl transferase to transfer the polypeptide to a water molecule, causing the release of the polypeptide - The mRNA, deacylated tRNA and RFs leave ribosome and ribosome dissociate into 30S and 50S for recycling. - The functions of RF3 is to accelerate termination - In eukaryotes, a single eRF catalyzes the termination step; GTP is required

elongation in prokaryotes step 2: peptide formation

- The amino group on the amino acid at A site displaces the tRNA at P site to form peptide bond -This reaction is catalyzed by the peptide transferase activity of the 23S rRNA of the ribosome (ribozyme) - The peptide chain will end up at A site; while the tRNA at P site will become uncharged, or deacylated. -The process is similar in eukaryotes.

in splicing, what is a Lariat?

- a looped structure intermediate that occurs in the mRNA during splicing. - cleavage at the 5' end of the intron results in the formation of a branched A, near the 3' end of the intron, that is , the 5'p reacts at 2' A forming a branched structure known as a lariat - then, the 3' end of the intron is cleaved as the two exons are spliced i don't get this ask in OH

What is the process of splicing in RNA processing?

- a number of genes in higher organisms appear to be split: part of the DNA (nonsense stretches) don't code for functional RNA - the cell produces full RNA transcript of the DNA and then appears to splice out the nonsense sequence before sending the RNA to the cytoplasm

describe the structure of tRNA?

- clover leave secondary structure - "L" shaped terry conformation fits snugly into the ribosome - acceptor stem is where the amino acid binds - anticodon loop is where the codon lines up - not always correctly paired! what is the significance of not always being correctly paired

RNA transcription reaction requires what 3 elements?

DNA, 4 ribonucleoside triphosphate, and RNA polymerase

what is RNA polymerase?

RNA polymerase is an enzyme that binds to DNA during transcription and separates or unwinds the DNA strands.

what is an RNA DNA hybrid?

RNA/DNA hybrids form when RNA hybridizes with its template DNA generating a three-stranded structure known as the R-loop. called "hybrid duplexes"

What happens during rho-dependent termination of RNA transcription in prokaryotes?

Rho is a protein factor that appears to be active as a hexamer and hydrolysis of nucleoside triphosphate is necessary. The exact mechanism of how the rho-protein terminates transcription has not been defined.

toxins that target mammalian protein synthesis: what do Ricin and Diphtheria toxin do?

Ricin = (from castor beans) and related to N-glycosidases cleave a single adenine from the backbone of the large rRNA Diphtheria toxin = a protein that enters the cell and catalyzes the ADP-ribosylation and inactivation of EF-2

what is RNA processing?

The RNA copy of a protein encoding gene must be modified in several ways before it can be transported out of the nucleus and translated into protein. only in eukaryotes

mRNA editing

can start with the same gene, ex. apo-B gene, change the nucleotide sequence in mRNA, and end up encoding different proteins! ex. encode liver and intestinal cells.

mRNA transcribed from DNA are understood by the cell in triplets called ______

codons

what is genetic code?

collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis

in one variation of splicing called _____ splicing, nonconsecutive exons are spliced. this results in similar but nonidentical proteins called ______.

alternate splicing aka splice choice results in isoforms

what is a synonymous mutation in genetic code?

another nuclease is substituted, but it doesn't change the meaning of the codon (same codon)

translation of mRNAs beings at what codon? what is the orientation of the anti-codon?

at the AUG start codon the anti-codon is oriented anti-parallel

the core enzyme of prokaryotic RNA polymerase contains what subunits? the holoenzyme contains what? what is the purpose of each enzyme?

core = alpha, beta, beta' 2 alpha, one of each beta holo = sigma holoenzyme needed for initiation, but core enzyme is sufficient for elongation (wouldn't know where to start on its own)

in eukaryotic transcription initiation, DNA strands contain cis acting sequences that bind proteins that do either of what two things? these sequences are orientation and position dependent/independent? they interact with RNA polymerase by _______.

either enhance (enhancers) or repress (silencers) transcription. So either increase or decrease transcription. independent looping

how do eukaryotic and prokaryotic protein translation differ?

eukaryotic: - transcription occurs in nucleus - translation occurs in cytoplasm (cytosol &RER)-- so transcription must be finished before translation - mRNA must be processed prokaryotic: - coupled transcription and translation in cytoplasm - no compartmentalization - no mRNA processing (ex. removal of introns) - translation can happen while transcription is still going on

the coding sequences of split genes are called _____ (for expressed regions), whereas their untranslated interveningg sequences are known as _____

exons introns

what two enzymes are involved in tRNA processing, and what addition?

exonuclease and endonuclease, as well as a 3' terminal addition in the image, you can see that the endonuclease and exonuclease removes the intron sequence. im not sure which one it really is ask in OH

T/F: Synonymous, missense, nonsense, and frameshift mutations are all substitutions?

false! The first three are substitutions, and the last one is insertion

T/F: mRNA processing doesn't do anything to ensure the correct coding sequence.

false! its whole point is to ensure correct coding sequence!!!

T/F protein translation requires energy from ATP but not GTP

false, protein translation requires energy from ATP and GTP

Why is RNA transcription necessary?

for gene expression

What is a lariat in RNA splicing?

forming a loop structure that helps get rid of the intron during splicing

proteins are translate in what direction on mRNA?

from 5' to 3' on mRNA

what is the "hammerhead" structure of viral RNA?

Certain paired regions in the RNA can form a hammer head shape it is a ribozyme

____ serves as a template for transcription?

DNA

eukaryotic RNA transcription operates by recruitment of ______?

RNA polymerase I'm confused about this image. ask in OH

Canonical (______) base-pairing allows for effective and efficient base pairing of the tRNA with the mRNA codon.

Watson-Crick the usual pairing: GC / UA

what is micro RNA (miRNA)

A microRNA is a small non-coding RNA molecule found in plants, animals and some viruses, that functions in RNA silencing and post-transcriptional regulation of gene expression. miRNAs function via base-pairing with complementary sequences within mRNA molecules. They are encoded by genes.

What happens during rho-independent termination of RNA transcription in prokaryotes?

(a) A stable GC-rich palindrome is required which allows the formation of an RNA stem-loop structure upstream of the 3' terminus. (b) A stretch of several (6-7) consecutive adenine residues near the terminus so the transcript contains a corresponding stretch of poly U. (c) The palindrome sequence leads to the formation of a stem-loop structure in the nascent RNA causing the polymerase to pause and also disrupting the 5' half of the RNA-DNA helix. The remaining portion of the RNA-DNA hybrid contains rU-dA which is very unstable and, therefore, dissociates, leading to the release of the transcript, and reassociation of the single-stranded regions of the DNA template. Subsequent release of polymerase completes termination. The strength of the termination signal can be increased by increasing either the length of the GC stretch or the poly U.

initiation of translation in eukaryotes?

- 40S ribosome and initiation factors bind to Met- tRNA before binding to mRNA, unlike in prokaryotes -Contains many more initiation factors and needs more ATP during scanning The ribosomal complex recognizes the 5' 7- methylguanosine cap structure instead of sequences -The starting site is usually the first AUG after the cap structure -Met-tRNA is used as the start codon - mRNA in circularized

what happens during RNA interference?

- double stranded RNase cuts double-stranded RNA into small pieces in the nucleus - once exported to the cytoplasm, another double strand RNase called DICER generates small double stranded RNA of about 21 bp - the small RNA is bound by a protein complex called RISC that generates a single stranded RNA (RISC remains bound) that basepairs with an mRNA target - LEFT if there is a perfect complementarity (siRNA), the target mRNA is cleaved by the RISC complex -RIGHT: if there is imperfect complementarity (miRNA), the translation of the target mRNA is repressed

What is the process of polyadenylation in RNA processing?

- in nucleus, about 250 adenyl units are added to the 3' end of the mRNA precursor to form a poly-A trail - there is a signal at the 3' end of the pre-mRNA which is recognized by a specific endonuclease - after cleavage at this site, the poly-A tail is added to mRNA

what are the three main components of the translation apparatus?

- mRNAs carry the Genetic Codes needed for translation - Ribosomes are the catalytic sites of translation - tRNAs are adapters that bring the necessary amino acids

What is the process of capping in RNA processing?

- most eukaryote mRNA molecules modified at the 5' end by the addition of a cap - guanine nucleotide is added to form usual 5'-5' linkage. - then, methyl groups added to terminal guanine residue, and 2'OH at the adjacent nucleotide. (shown in image)

why must splicing be precise?

- must be very precise, or else there would be a change in the message and then in the actual protein - the specificity of splicing is probably due in part to the sequence of bases at the junction site

what is the purpose of polyadenylation in RNA processing?

- polyadenylation is necessary for maturation of most mRNA molecules, but some species of mRNA don't have a poly-A tail - a specific endonuclease cleaves the RNA down stream of the AAUAAA signal sequence - polyA polymerase adds about 250 A residues

In prokaryotic RNA transcription, in the -10 region of DNA, most genes contain a sequence that closely approximates what sequence? what sequence is resembled in the -35 region?

-10 has TATAAT (TA box) - although ,very few genes contain exactly that sequence -35 has TTGACA (GA box)

how many AT are required for the synthesis of a 100 AA protein in bacteria? for: 1. activation 2. initiation 3. elongation 4. translocation 5. termination 6. total are more or less ATP required in eukaryotes?

1. 200 (break 200 ATP bonds 2. 1 (IF2 uses 1 ATP) 3. 99 (EF-Tu) 4. 99 5. 0 6. 399! MORE!

What 4 features distinguish eukaryotic RNA transcription from prokaryotic transcription?

1. DNA that has to be transcribed is wound around a histone core 2. it is transcribed by one of 3 RNA polymerases 3. the primary RNA transcript is processed within the nucleus into the finished RNA. 4. Only after transport of the RNA, presumably through a nuclear pore, does translation occur in the cytoplasm. In bacteria, all precursor rRNA and tRNA are processed but mRNA only rarely requires processing.

How can miRNA or siRNA (small interference RNA) inhibit RNAs?

1. RISC (RNA protein complex cuts endonuclease activity), cleaving RNA. 2. miRNP (micro RNA RNP complex) cleaves or blocks gene expression -- called translational repression

components for E. coli protein synthesis, main stages?

1. activate amino acids 2. initiate 3. elongate 4. terminate & release 5. folding and post translational processing know general idea of the components

the formation of what two compounds are used int eh activation of amino acids?

1. aminoacyl-AMP 2. Aminoacyl-tRNAs (syntheses) use ATP to form form in cytosol, not ribosome

RNA processing usually consists of what four actions?

1. cleavage, 2. cut and splice 3. modification (usually methylation of bases or ribose) 4. terminal additions

_________ nuclear RNA (hnRNA) contains the precursor of mRNA in eukaryotes. Most mature RNA molecules have undergone what three processes?

1. heterogenous (mixed) 2. RNA splicing, capping, and polyadenylation

what are the 4 steps in the initiation events and elongation of prokaryotic RNA transcription?

1. holoenzyme (sigma) binds to promoter region to form a closed binary complex. 2. short region of DNA (15 bp) melts to form an open binary complex. 3. Upon initial RNA synthesis, a ternary complex is formed and the sigma factor is released. 4. Core enzyme moves along the gene as elongation proceeds. New RNA depicted in orange, being transcribed from 5' to 3' end. in image, green is sigma and blue is core enzyme.

Several types of inhibitors enhance our understanding of the eukaryotic and prokaryotic transcription process.What do each of the following inhibitors do? 1. actinomycin D 2. alpha-amanitin 3. rifampicin which one(s) can be used medically?

1. intercalates (inserts) between DNA strands and interferes with elongation. It inhibits all transcription in bacteria and humans, so is not medically useful, but is useful in research. 2. displays selective inhibition of various mammalian RNA polymerases, specifically pol II. It targets eukaryotes so cannot be used medically. 3. binds to the beta subunit (active site) of bacterial RNA polymerase. Only targets bacteria, so can be used medically. Is used to kill Tb!

characteristics of the genetic code: 1. Each codon specifies only _____ amino acid 2. The codons do not ______. 3. Reading _____ is a sequence of consecutive and non-overlapping triplets. 4. Known as a "________" code. (64 codons for 20 Amino acids) 5. The mRNA strand is read from the ___ to the ___ end. 6. Translation starts from initiation codon: ____ (Met) 7. Translation terminates at ____ (UAA, UAG, and UGA) which do not code for an amino acid. 8. Mutations or errors in the DNA may change _____ and form incorrect protein eventually.

1. one 2. overlap 3. frame 4. degenerate 5. 5' to 3' 6. AUG 7. stop codons 8. mRNA

during RNA transcription, what is the direction of synthesis along the DNA template strand?

3' to 5'. Initiation at the end of the gene is 3'. Termination at the end of the gene is 5'. But, RNA gets synthesized in 5' to 3' direction (antiparallel.)

in what direction is new RNA transcribed from template DNA?

5' to 3'

in what direction are mRNAs read and translated?

5' to 3' direction

for a tRNA anti-codon (5>ICG<3), which mRNA codon(s) could be recognized? 5>CGA<3 5>GCI<3 5>CGG<3 all of the above none of the above

5>CGA<3

what is a 5' cap, structurally?

7-methylguanosine on the 5' of RNA

initiation in prokaryotes using fMET. the first step uses what molecule?

ATP! It turns to ANP Ribosome helps locate the initiation site. not sure what to get from rest of the image

what 4 ribonucleoside triphosphate are the substrates for the transcription reaction?

ATP, GTP, UTP, CTP

what is the start codon? what else does it encode?

AUG also encodes Met

Of the four subunits for prokaryotic RNA polymerase, which is biggest?

B' an dB are largest. alpha are smallest

What is Wobble-base pairing?

Deviations from standard Watson-Crick base-pairing rules in codon-anticodon interactions at the 3' position of the codon - occurs on the 3rd base of codons (5' end) - the first two bases of an mRNA codon always form strong Watson-Crick base pairs - the first base of the anticodon determine the number of codons recognized by the tRNA be familiar with this chart for wobble base pairing!

T/F: Like DNA transcription, RNA transcription requires a primer.

False! Unlike DNA transcription, RNA transcritipion does NOT require a primer

_____ catalyzes the RNA transcription process.

RNA polymerase

what are the cellular transcripts for type I, II, and III RNA polymerase in eukaryotes?? how is each affected by alpha amanitin (inhibits RNA polymerase)

I; 18S, 5.8S, and 28S rRNA (image) II: mRNA precursors (hnRNA) III: tRNA and 5S rRNA I: insensitive II: strongly inhibited III: only inhibited by high concentrations

eukaryotic transcription initiation requires RNA pol _____ and at least 6 additional protein complexes including TFIID, which is what?

II TFIID = transcription factor for DNA repair

what are the steps of initiation of protein translation in prokaryotes?

Initiation factor (IF)-1 and IF-3 bind to 30S subunit Step 1: 30S bind to SD sequence on mRNA; IF-3, the anti-association factor, prevents 50S premature binding IF-1 binds to the A site to prevent premature tRNA binding Step 2: GTP-IF2-fMet-tRNA join the ribosomal subunit; Codon-anticodon pairing at P site Step 3: 50S ribosome subunit join; GTP hydrolyzes to GDP and Pi; IFs depart from the ribosome

in eukaryotic transcription initiation, many but not all DNA sequences have a _____ at -30.

TATA box

what si a frameshift mutation in genetic code?

addition or deletion of one or more bases disrupts the reading frame

what is RNA transcription?

Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA)

T/F: In some cases of splicing, the intron acts as the catalyst for splicing.

Yes!!

What does EPA mean on a ribosome?

a = aminoacyl site p = peptidal site e = exit site

what is a nonsense mutation in genetic code?

a DNA sequence change that results in a stop codon being encoded

What complex mediates splicing?

a complex structure of specific nuclear proteins along with small nuclear RNAs (snRNA) called a spliceosome each spliceosome contains several snRNPs which are snRNAs completed with specific nuclear proteins

what is the end product of protein translation?

a polypeptide chain of amino acids, starting from the amino terminal (N-ter) and ending with the carboy terminal (C-ter)

what is a consensus sequence?

a sequence of DNA having similar structure and function in different organisms for prokaryotic promotes, is at -35 and -10. They are the GA and TA box, shown in the graph. The orange bars represent the purine at +1.

Most eukaryotic genes contain introns. However, ______ and _____ genes do not. The number of introns per genes varies (beta-globing has 2, whereas collagen has over 40).

histone & interferon

in addition to synthetic site, most of the synthetases contain _____ sites

hydrolytic

real-ilife example: hemoglobin mutations

i don't really understand this slide. protein length increases due to mutated stop codon

what is a dicer?

in image, dicer is an endoribonuclease that slices pre-microRNA into double stranded RNA fragments called siRNA and miRNA

Termination of transcription in eukaryotes is always rho dependent or independent?

independent!! and termination is similar to the mechanisms for prokaryotes

what are the names of the 3 steps of RNA transcription?

initiation, elongation, and termination

where is a spliceosome attached?

it is formed attached to the splice site of a hnRNA molecule the U1 and U2 help the spliceosome determine where to splice!

eukaryotes vs. prokaryotes translation? 1. ribosome 2. amino acid carried by initiator tRNA 3. shine-delgarno sequence in mRNA 4. simultaneous translation and transcription?

look at figure

what is monocistronic vs. polycistronic mRNA translation? are more eukaryotes mono or poly? what about bacteria?

mono = encode one gene, make one protein poly = encode multiple genes on the same mRNA and make multiple proteins most eukaryotes are mono; bacteria are poly

is a spliceosome used in rRNA processing?

no!

for a tRNA anti-codon (5>IGC<3), which mRNA codon(s) could be recognized? 5>CGA.3 5>GCI<3 5>GCG<3 all of the above none of these above

none of the above

each codon codes for how many amino acids?

only 1!

what are shine-dalgarno sequence?

pair with 16s rRNA.

multiple ribosome (polysome) can translate one mRNA simultaneously. what is a polysome? polysome is usually an indication of what?

polysome = multiple ribosomes bound to the same mRNA transcript polysome present means there is active translation! image is electron microscopy picture of polysome on mRNA

Production of functional RNA usually requires _____ and _______ of the initial transcript for all species of RNA.

post transcriptional modifications and processing

familiarize with eukaryotic vs. prokaryotic initiation factors

prokaryotic only has 3, eukaryotic has many more.

prokaryotic RNA polymerases lack a separate ______ 3' to 5' exonuclease active site

proofreading

In prokaryotic RNA transcription, the first nucleotide to be transcribed (+1) is usually what type of nuclease?

purine

Termination of prokaryotic transcription may be either ____ or _____

rho-dependent or rho independent.

what connects mRNA, amino acids, and tRNA?

ribosomes!

catalytic RNA molecules are called _____

ribozymes

what is the math behind having 64 possible amino acids?

since we have 3 base condons, 4 nucleotides: 4³ = 64 possible amino acids!

what is a missense mutation in genetic code?

single DNA sequence change that results in a different amino acid being encoded

what are siRNAs?

small, double stranded interfering RNAs that acts to silence translation

Ribosomes catalyze what?

the protein bond formation! be familiar with this chart.

what is degeneracy of the genetic code?

the same amino acid can correspond to multiple codons

what subunits is E.coli RNA polymerase composed of?

these subunits interact to provide specific initiation, polymerization, and termination of RNA. a. Beta' subunit = binds to double stranded DNA template ; contains an active site b. Sigma subunit = recognizes promoter & facilitates initiation of synthesis at the promoter site; ensures that RNA polymerase binds stable only at promoters c. Beta subunit = contains active site d. two alpha subunits = may be involved in transcriptional regulation

at lease how many RNA polymerases exist in the mammalian nucleus? what are they?

three RNA polymerase I, II, II they have catalytic characteristics in common, but are also different. The different effects of alpha-amanitin and salts on these enzymes has been useful in studying their activities.

how many stop codons are there? what are they?

three UAA UAG UGA

in rRNA processing, multiple rRNAs are derived from single _____

transcripts! ask what this pic means in OH