Question

Rho shows base preference although it doesn’t have any concensus cis binding sequence. Which region will be expected to bind Rho better?

(a) G and C rich region

(b) A and T rich region

(c) Region rich in C and poor in G

(d) Region rich in A and poor in T

The question was posed to me during an interview for a job.

Question is taken from Transcription in Prokaryotes : Termination topic in division Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

The correct choice is (c) Region rich in C and poor in G

For explanation I would say: Rho binds best to regions having high C content as much as 41% and low G content as much as 14%. As in RNA there is no compulsory base pairing the amount of G is not necessary equal to the amount of c.