The diagram below shows the DNA sequence of a gene which is expressed only in th
ID: 39797 • Letter: T
Question
The diagram below shows the DNA sequence of a gene which is expressed only in the skin of the Jackalope, a diploid eukaryote. Shown is DNA sequence from close to the transcriptional start site, as well as some upstream sequence. The first nucleotide transcribed is an A, and the corresponding A on the coding strand is underlined. Two other sequences in this region are underlined.
Below the sequence is shown the structure of several pieces of DNA that I tested for their ability to initiate transcription. Construct a is the wild-type sequence and b through f either contain small deletions (b-d) or point mutations (e, f). At the right are indicated the relative levels of transcription for each construct, in Arbitrary Units
i. For each mutant construct, indicate: what sequence element might be affected; what protein is thought to bind to that element; and why the expression level is changed to the extent shown.
b:
c:
d:
e:
f:
The diagram below shows the DNA sequence of a gene which is expressed only in the skin of the Jackalope, a diploid eukaryote. Shown is DNA sequence from close to the transcriptional start site, as well as some upstream sequence. The first nucleotide transcribed is an A, and the corresponding A on the coding strand is underlined. Two other sequences in this region are underlined. Below the sequence is shown the structure of several pieces of DNA that I tested for their ability to initiate transcription. Construct a is the wild-type sequence and b through f either contain small deletions (b-d) or point mutations (e, f). At the right are indicated the relative levels of transcription for each construct, in Arbitrary Units i. For each mutant construct, indicate: what sequence element might be affected; what protein is thought to bind to that element; and why the expression level is changed to the extent shown. b: c: d: e: f:Explanation / Answer
the sequence is WILD TYPE CONSISTS OF SEQUENCE WHICH SPLICE SQUENCES { GGGGGG} ARE PRESENT ,IT IS A NASCENT TRANSCRIPT IT IS RELATIVLEY 10 UNITS
THE SEQUENCE B ;
the GGGGG SEQUENCE IS THE SHINE DALGARNO SEQUENCES , WHICH IS LOCATED UPSTREAM TO TATAA BOX , IT DOES NOT INCREASE THE INTIATE TRANCRIPTS BUT IT INCREASES THE NUMBER OF TRANSCRIPTS .
THE SEQUENCE C ;
THERE IS NO TATAAA WHICH IS A BINDING FACTOR FOR TATA BOX IN THE UPSTREAM PROMOTER REGION ,HENCE THE RELATIVE ACTIVITY OF THE GENE IS REDUCED ,EVEN THOUGH THE GGGG REGION IS PRESENT . transcription intiation is very less
THE SEQUENCE D';
THERE IS NO GGGG RICH REGION , AND ALSO TATAA IS THE BINDING FACTOR IS ALSO ABSENT IN THE PROMOTER REGION E UPSTREAM POSITION . SO THERE IS NO RELATIVE GENE ACTIVITY
THE SEQUENCE E ;
THE PRESENCE OF GGGG RICH REGION AND THE REPLACEMENT WITH T , IN THE REGION IT BECOMES TATAAT REGION ,IS CALLED PRIBNOW BOX WHICH IS A PROMOTER
IT IS PRESENT IN BACTERIA WHERE RNA POLYMERASE WILL BIND TO THAT REGION .
THE SEQUENCE F;
THERE IS THE PRESENCE OF GGGG RICH REGION ,BUT THERE IS A MUTATION IN THE WHERE T IS REPLACED BY G , THE SEQUENCE BECOMES GATAA ,CAUSES THE RETARDATION OF DNASE 1 ENZYME , HENECE THERE IS VERY LESS ACTIVITY .