8k3f
From Proteopedia
Crystal structure of the recombination mediator protein RecR from Campylobacter jejuni
Structural highlights
FunctionA0A2U0QSA2_CAMJU May play a role in DNA repair. It seems to be involved in an RecBC-independent recombinational process of DNA repair. It may act with RecF and RecO.[HAMAP-Rule:MF_00017] Publication Abstract from PubMedThe recombination mediator complex RecFOR, consisting of the RecF, RecO, and RecR proteins, is needed to initiate homologous recombination in bacteria by positioning the recombinase protein RecA on damaged DNA. Bacteria from the phylum Campylobacterota, such as the pathogen Campylobacter jejuni, lack the recF gene and trigger homologous recombination using only RecR and RecO. To elucidate the functional properties of C. jejuni RecR (cjRecR) in recombination initiation that differ from or are similar to those in RecF-expressing bacteria, we determined the crystal structure of cjRecR and performed structure-based binding analyses. cjRecR forms a rectangular ring-like tetrameric structure and coordinates a zinc ion using four cysteine residues, as observed for RecR proteins from RecF-expressing bacteria. However, the loop of RecR that has been shown to recognize RecO and RecF in RecF-expressing bacteria is substantially shorter in cjRecR as a canonical feature of Campylobacterota RecR proteins, indicating that cjRecR lost a part of the loop in evolution due to the lack of RecF and has a low RecO-binding affinity. Furthermore, cjRecR features a larger positive patch and exhibits substantially higher ssDNA-binding affinity than RecR from RecF-expressing bacteria. Our study provides a framework for a deeper understanding of the RecOR-mediated recombination pathway. Structural and Biochemical Analysis of the Recombination Mediator Protein RecR from Campylobacter jejuni.,Lee SJ, Ahn SY, Oh HB, Kim SY, Song WS, Yoon SI Int J Mol Sci. 2023 Aug 18;24(16):12947. doi: 10.3390/ijms241612947. PMID:37629127[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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