The bridge helix coordinates movements of modules in RNA polymerase

Abstract

Abstract The RNA polymerase 'bridge helix' is a metastable α-helix that spans the leading edge of the enzyme active-site cleft. A new study published in BMC Biology reveals surprising tolerance to helix-disrupting changes in a region previously thought crucial for translocation, and suggests roles for two hinge-like segments of the bridge helix in coordinating modules that move during the nucleotide-addition cycle. See Research article: http://www.biomedcentral.com/1741-7007/8/134