2026-04-13T03:29:44Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1140492026-04-09T19:01:03Zcom_2072_1057col_2072_478781col_2072_478908col_2072_478917

00925njm 22002777a 4500 dc Boer, Roeland author Ruiz Masó, José Angel author Petoukhov, Maxim author Machón Sobrado, Cristina author Svergun, Dmitri author Orozco López, Modesto author Solar, Gloria del author Coll, Miquel author 2017-07-19T10:17:54Z 2017-07-19T10:17:54Z 2016-02-15 2017-07-19T10:17:54Z DNA replication initiation is a vital and tightly regulated step in all replicons and requires an initiator factor that specifically recognizes the DNA replication origin and starts replication. RepB from the promiscuous streptococcal plasmid pMV158 is a hexameric ring protein evolutionary related to viral initiators. Here we explore the conformational plasticity of the RepB hexamer by i) SAXS, ii) sedimentation experiments, iii) molecular simulations and iv) X-ray crystallography. Combining these techniques, we derive an estimate of the conformational ensemble in solution showing that the C-terminal oligomerisation domains of the protein form a rigid cylindrical scaffold to which the N-terminal DNA-binding/catalytic domains are attached as highly flexible appendages, featuring multiple orientations. In addition, we show that the hinge region connecting both domains plays a pivotal role in the observed plasticity. Sequence comparisons and a literature survey show that this hinge region could exists in other initiators, suggesting that it is a common, crucial structural element for DNA binding and manipulation. Duplicació de l'ADN Models moleculars Radiocristal·lografia DNA replication Molecular models X-ray crystallography Conformational plasticity of RepB, the replication initiator protein of promiscuous streptococcal plasmid pMV158