Seminar by Max Gottesman

Speaker: Max Gottesman, Columbia University New York
Host: Steen Pedersen, Biomolecular Sciences

In all living cells, transcription, translation and replication must be coordinated. Studies in vitro suggest that transcription and translation are physically coupled in E. coli by the NusG protein. The NusG NTD binds RNAP, whereas the NusG CTD binds ribosomal protein S10. We present a cryo-EM structure showing NusG CTD bound to S10 in an intact 70S ribosome. We find that NusG is required for coupling in vivo. Uncoupling is induced by amino acid starvation, and leads to Rho-dependent intragenic transcription termination. Uncoupling depends on tmRNA, which both releases stalled ribosomes and competes with NusG for binding to S10. Persistent coupling increases sensitivity to DNA damaging agents, possibly by blocking access of DNA repair enzymes. Surprisingly, relA mutants are uncoupled. We propose that uncoupling slows the rate of translation by the lead ribosome, thereby activating RelA.

Some of Dr Gottesman’s recent publications are listed at http://www.microbiology.columbia.edu/faculty/gottesman.html