Trans-complementation by the RecB nuclease domain of RecBCD enzyme reveals new insight into RecA loading upon χ recognition

Theetha L. Pavankumar, C. Jason Wong, Yun Ka Wong, Maria Spies, Stephen C. Kowalczykowski
2023 · doi:10.1101/2023.05.14.540676
preprint OA: closed CC-BY-NC-4.0
📄 Open PDF View at publisher

Abstract

Summary The loading of RecA onto ssDNA by RecBCD is an essential step of RecBCD-mediated homologous recombination. RecBCD facilitates RecA-loading onto ssDNA in a χ-dependent manner via its RecB nuclease domain (RecB n ). Before recognition of χ, RecB n is sequestered through interactions with RecBCD. It was proposed that upon χ-recognition, RecB n undocks, allowing RecB n to swing out via a contiguous 70 amino acid linker to reveal the RecA-loading surface, and then recruit and load RecA onto ssDNA. We tested this hypothesis by examining the interactions between RecB n (RecB 928–1180 ) and truncated RecBCD (RecB 1–927 CD) lacking the nuclease domain. The reconstituted complex of RecB 1–927 CD and RecB n is functional in vitro and in vivo . Our results indicate that despite being covalently severed from RecB 1–927 CD, RecB n can still load RecA onto ssDNA, establishing that RecB n does not function at the end of its flexible linker. Instead, RecBCD undergoes a χ-induced intramolecular rearrangement to reveal a RecA-loading surface.

My notes (saved in your browser only)

Citation neighborhood (no data yet)

We don't have any in-corpus citations linked to this paper yet. The paper's references may be in our DB but unresolved to ``paper_id`` (resolution happens at ingest when the cited DOI matches a row we already have). Run the cross-source citation reconcile pass to retry.

References (36)

Source provenance

crossref
last seen: 2026-06-18T06:36:13.224601+00:00
europepmc
last seen: 2026-05-19T01:45:01.086888+00:00
unpaywall
last seen: 2026-05-22T02:00:06.705733+00:00
License: CC-BY-NC-4.0