Relaxosome function and conjugation regulation in F‐like plasmids – a structural biology perspective

摘要: Summary The tra operon of the prototypical F plasmid and its relatives enables transfer a copy to other bacterial cells via process conjugation. Tra proteins assemble form transferosome, transmembrane pore through which DNA is transferred, relaxosome, complex DNA-binding at origin transfer. F-like conjugation characterized by high degree specificity in interactions components, tightly regulated transcriptional, translational post-translational levels. Over past decade, X-ray crystallography conjugative components has yielded insights into both regulatory mechanisms. Conjugation repressed FinO, an RNA chaperone increases lifetime small RNA, FinP. Recent work resulted detailed model FinO/FinP discovery family FinO-like chaperones. Relaxosome include TraI, relaxase/helicase, TraM, mediates signalling between transferosome relaxosome for initiation. The structures TraI TraM bound oriT reveal basis specific recognition their cognate plasmid. Specificity also exists with protein TraD.