Transcription antitermination: the λ paradigm updated

Publisher Website
Google Scholar
Abstract
Coliphage λ employs systems of transcription termination and antitermination to regulate gene expression. Early gene expression is regulated by the phage‐encoded N protein working with a series of Escherichia coli proteins, Nus, at RNA sites, NUT, to modify RNA polymerase to a termination‐resistant form. Expression of λ late genes is regulated by the phage‐encoded Q antitermination protein. Q, which appears to use only one host factor, acts at a DNA site, qut, to modify RNA polymerase to a termination‐resistant form. This review focuses on recent studies which show that: (i) N can mediate antitermination in vitro, independent of Nus proteins, (ii) Early genes in another lambdoid phage HK022 are also regulated by antitermination, where only an RNA signal appears necessary and sufficient to create a termination‐resistant RNA polymerase. (iii) A part of the qut signal appears to be read from the non‐template DNA strand. (iv) A host‐encoded inhibitor of N antitermination appears to act through the NUT site as well as with the α subunit of RNA polymerase, and is antagonized by NusB protein.

This publication has 0 references indexed in Scilit: