Chapter 24, Problem 20E

(a)

Summary Introduction

To calculate: The copies of the 6-bp recognition sequences the trp repressor would expect to occur in the E. coli chromosome.

Concept introduction: E. coli chromosome consists of one circular chromosomal DNA, in which it has 4639 kb of genomic information. Its chromosome contains many genes that regulate the cellular metabolic activities. One such gene is the tryptophan repressor gene that maintains and controls the synthesis pathways of the amino acid-tryptophan.

(b)

Summary Introduction

To explain: The reason why it is advantageous for the trp repressor to be a dimer that recognizes two adjacent 6-bp sequences.

Concept introduction: E.coli chromosome consists of one circular chromosomal DNA, in which it has 4639 kb of genomic information. Its chromosome contains many genes that regulate the cellular metabolic activities. One such gene is the tryptophan repressor gene that maintains and controls the synthesis pathways of the amino acid-tryptophan.