Homologous-pairing activity of the Bacillus subtilis bacteriophage SPP1 replication protein G35P |
| |
Authors: | Ayora Silvia Missich Riccardo Mesa Pablo Lurz Rudi Yang Shixin Egelman Edward H Alonso Juan C |
| |
Affiliation: | Departmento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Campus Universidad Autónoma de Madrid, Madrid 28049, Spain. |
| |
Abstract: | Genetic evidence suggests that the SPP1-encoded gene 35 product (G35P) is essential for phage DNA replication. Purified G35P binds single-strand DNA (ssDNA) and double-strand (dsDNA) and specifically interacts with SPP1-encoded replicative DNA helicase G40P and SSB protein G36P. G35P promotes joint molecule formation between a circular ssDNA and a homologous linear dsDNA with an ssDNA tail. Joint molecule formation requires a metal ion but is independent of a nucleotide cofactor. Joint molecules formed during these reactions contain a displaced linear ssDNA strand. Electron microscopic analysis shows that G35P forms a multimeric ring structure in ssDNA tails of dsDNA molecules and left-handed filaments on ssDNA. G35P promotes strand annealing at the AT-rich region of SPP1 oriL on a supercoiled template. These results altogether are consistent with the hypothesis that the homologous pairing catalyzed by G35P is an integral part of SPP1 DNA replication. The loading of G40P at a d-loop (ori DNA or at any stalled replication fork) by G35P could lead to replication fork reactivation. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|