Which subunits of the recbcd trimer show helicase structure and function?
What is the role of RecBCD? Describe the specific steps these proteins(RecA and RecBCD) carry out?
Answer= Role of RecBCD is as follows: 1.The RecBCD enzyme of Escherichia coli is a helicase -nuclease that initiates the repair of double-stranded DNA breaks by homologous recombination. 2.It also degrades linear double-stranded DNA ,protecting the bacteria from phages and extraneous chromosomal DNA. 3.The RecBCD enzyme is regulated by a cis-acting DNA sequence known as Chi that activates its recombination promoting functions. The specific steps these proteins(RecA and RecBCD) carry out are as follows: RecBCD- is a large i.e.330 kDa complex of three polypeptides with both DNA-unwinding (helicase) and DNA hydrolysis (nuclease) activities. Beginning at the DNA double-strand end,it unwinds DNA and at a special nucleotide sequence called Chi,makes a new 3′ end at which it begins loading multiple RecA protein molecules onto the single stranded DNA.
RecA -RecA promotes the exchange of this ssDNA for its equal in an intact homologous DNA molecule
Which subunits of the recbcd trimer show helicase structure and function?