In:
Acta Crystallographica Section F Structural Biology Communications, International Union of Crystallography (IUCr), Vol. 78, No. 11 ( 2022-11-01), p. 378-385
Abstract:
Bacterial capsular polysaccharides provide protection against environmental stress and immune evasion from the host immune system, and are therefore considered to be attractive therapeutic targets for the development of anti-infectious reagents. Here, we focused on CapG, one of the key enzymes in the synthesis pathway of capsular polysaccharides type 5 (CP5) from the opportunistic pathogen Staphylococcus aureus . Sa CapG catalyses the 2-epimerization of UDP- N -acetyl-D-talosamine (UDP-TalNAc) to UDP- N -acetyl-D-fucosamine (UDP-FucNAc), which is one of the nucleotide-activated precursors for the synthesis of the trisaccharide repeating units of CP5. Here, the cloning, expression and purification of recombinant Sa CapG are reported. After extensive efforts, single crystals of Sa CapG were successfully obtained which belonged to space group C 2 and exhibited unit-cell parameters a = 302.91, b = 84.34, c = 145.09 Å, β = 110.65°. The structure was solved by molecular replacement and was refined to 3.2 Å resolution. The asymmetric unit revealed a homohexameric assembly of Sa CapG, which was consistent with gel-filtration analysis. Structural comparison with UDP- N -acetyl-D-glucosamine 2-epimerase from Methanocaldococcus jannaschii identified α2, the α2–α3 loop and α10 as a gate-regulated switch controlling substrate entry and/or product release.
Type of Medium:
Online Resource
ISSN:
2053-230X
DOI:
10.1107/S2053230X22008743
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2022
detail.hit.zdb_id:
2175956-X
