NusE

NusE is a bacterial protein that serves as a component of the Nus factor complex, a group of proteins that regulate transcription termination and antitermination. In many bacteria, including Escherichia coli, NusE is identical to ribosomal protein S10, meaning the same polypeptide serves dual roles in transcription regulation and ribosome structure.

As part of the Nus factor complex, NusE works with NusA, NusB, and NusG to influence RNA polymerase behavior at certain operons. The Nus factors can promote antitermination, enabling RNA polymerase to read through termination signals under specific conditions. NusE’s interaction with NusB and other factors helps recognize RNA elements such as boxA, contributing to the formation of a transcription-translation–coupled regulatory state.

In its ribosomal role, NusE (as S10) is a component of the 30S ribosomal subunit and participates in normal protein synthesis. The dual identity of NusE links transcriptional regulation with translation, reflecting a coordinated coupling of the two processes in bacteria.

Genetically, nusE refers to the gene encoding this protein. Because NusE and ribosomal S10 are the same polypeptide in many species, mutations or altered expression can affect both translation efficiency and transcription antitermination, illustrating the interconnected nature of gene expression in bacteria. The NusE/S10 protein is broadly conserved across bacterial lineages, underscoring its fundamental role in cellular physiology.

See also: NusA, NusB, NusG, boxA, ribosomal protein S10.