Structural basis of directionality control in large serine integrases

Shin, H, Pigli, Y, Peña Reyes, T, Bello, AJ ORCID: 0000-0002-6731-2047, Taiwo-Aiyerin, OT ORCID: 0009-0005-9946-7472, Fuller, JR, Olorunniji, FJ ORCID: 0000-0001-9389-2981 and Rice, PA ORCID: 0000-0002-3467-341X (2026) Structural basis of directionality control in large serine integrases. Molecular Cell. pp. 1-17. ISSN 1097-2765

Preview

Text Structural basis of directionality control in large serine integrases.pdf - Published Version Available under License Creative Commons Attribution. Download (10MB) | Preview

Abstract

Large serine integrases catalyze unidirectional insertion of large DNA payloads and, in the presence of a cognate recombination directionality factor (RDF), catalyze unidirectional excision. Understanding how directionality is enforced has been hampered by a lack of structural information. Here, we report 8 structures of SPβ integrase-DNA complexes along the integrative (−RDF) and excisive (+RDF) reaction pathways at resolutions extending to 3.15 Å. These include tetrameric intermediates before and after strand exchange and product-bound dimers for both pathways. We find that recombination-induced conformational changes and RDF-mediated repositioning of the integrase’s coiled-coil subdomain (1) dictate which pairs of DNA sites can be assembled into active synaptic complexes and (2) dictate which product complexes will be conformationally locked, preventing back reactions. Critically, we find that the synaptic complex in which excision occurs is fundamentally different from that in which integration occurs. These insights provide a framework for engineering improved genome editing tools.

Item Type:	Article
Uncontrolled Keywords:	excision; genome editing; integration; large serine integrase; large serine recombinase; recombination directionality factor; site-specific DNA recombination; 3101 Biochemistry and Cell Biology; 31 Biological Sciences; Biotechnology; Genetics; 1.1 Normal biological development and functioning; 06 Biological Sciences; 11 Medical and Health Sciences; Developmental Biology; 31 Biological sciences; 32 Biomedical and clinical sciences; 42 Health sciences
Subjects:	R Medicine > RS Pharmacy and materia medica
Divisions:	Pharmacy and Biomolecular Sciences
Publisher:	Elsevier
Date of acceptance:	18 September 2026
Date of first compliant Open Access:	26 October 2026
Date Deposited:	26 Oct 2026 12:29
Last Modified:	26 Oct 2026 12:29
DOI or ID number:	10.1016/j.molcel.2026.09.028
URI:	https://researchonline.ljmu.ac.uk/id/eprint/29743

View Item