Craig Venter and his colleagues wanted to know if a complete

Craig Venter and his colleagues wanted to know if a complete genetic system could be produced using chemicals and a computer-generated DNA sequence. In 2010, they published an article describing the first self-replicating synthetic bacteria (M. mycoides JCVI-syn1.0) that has a computer sequence as its parent. (Creation of a bacterial cell controlled by a chemically synthesized genome. Science. 2010 Jul 2, 329 (5987):52-6. doi: 10.1126/science.1190719.) To verify that they had synthesized a new organism, Venter s team put DNA sequences in M. mycoides JCVI-syn1.0 that spell out secret messages. The same DNA sequence is printed out three times below, broken into different triplet reading frames. Use the SINGLE LETTER AMINO ACID sequence abbreviations in the codon table to uncover the secret message hidden in an open reading frame (ORF). The ORFs in this synthetic bacteria start with the codon 5\'ATG 3\' (written as 5\'AUG 3\' in the codon table, because it is the mRNA that is translated into amino acids). The DNA sequence below does not encode any introns. #1 5\' - AAA TTT ATC GTT CTG TGT TCT CTA CTC CAA TTG CAC GAC ACA TTG AA -3\' 3\' - TTT AAA TAG CAA GAC ACA AGA GAT GAG GTT AAC GTG CTG TGT AAC TT -5\' #4 #2 5\' - A AAT TTA TCG TTC TGT GTT CTC TAC TCC AAT TGC ACG ACA CAT TGA A -3\' 3\' - T TTA AAT AGC AAG ACA CAA GAG ATG AGG TTA ACG TGC TGT GTA ACT T -5\' #5 #3 5\' AA ATT TAT CGT TCT GTG TTC TCT ACT CCA ATT GCA CGA CAC ATT GAA -3\' 3\' TT TAA ATA GCA AGA CAC AAG AGA TGA GGT TAA CGT GCT GTG TAA CTT -5\' #6 What is the secret message? On which DNA strand (#1, #2, #3, #4, #5, or #6) did you find the secret message?

Solution

Refer to the followig table for converting triplet codon in to amino acid single letter code

Amino Acid

DNA codons

Isoleucine

I

ATT, ATC, ATA

L

V

F

TGT, TGC

A

GCT, GCC, GCA, GCG

G

P

T

Tyrosine  

H

E

Aspartic acid

D

K

R

Be careful, DNA strends are always read in 5\'--->3\' direction.

Look in to the table and convert all triplet codons in the given sequence into the following amino acid sequences (The Stop codon is represented as \"_\")

#1. KFIVLCSLLQLHDTL

#2. NLSFCVLYSNCTTH_

#3. IYRSVFSTPIARHIE

#4 (read in 5\'--->3\'). QCVVQLE_RTQNDKF

#5 (read in 5\'--->3\'). SMRAIGVENTER_I

#6 (read in 5\'--->3\'). FNVSCNWSREHRTIN

Answer a. The translated amino acid sequence from DNA strad #5 is SMRAIGVENTER I (5\'--->3\')

So the secret message is VENTER (the scientist\'s name)

Answer b. The secret code was on DNA strand # 5.

Amino Acid	SLC	DNA codons
Isoleucine	I	ATT, ATC, ATA
Leucine	L	CTT, CTC, CTA, CTG, TTA, TTG
Valine	V	GTT, GTC, GTA, GTG
Phenylalanine	F	TTT, TTC
Methionine	M	ATG
Cysteine	C	TGT, TGC
Alanine	A	GCT, GCC, GCA, GCG
Glycine	G	GGT, GGC, GGA, GGG
Proline	P	CCT, CCC, CCA, CCG
Threonine	T	ACT, ACC, ACA, ACG
Serine	S	TCT, TCC, TCA, TCG, AGT, AGC
Tyrosine	Y	TAT, TAC
Tryptophan	W	TGG
Glutamine	Q	CAA, CAG
Asparagine	N	AAT, AAC
Histidine	H	CAT, CAC
Glutamic acid	E	GAA, GAG
Aspartic acid	D	GAT, GAC
Lysine	K	AAA, AAG
Arginine	R	CGT, CGC, CGA, CGG, AGA, AGG
Stop codons	Stop	TAA, TAG, TGA