Global shape of SvGT, a metal-dependent bacteriocin modifying S/O-HexNActransferase from actinobacteria: c -terminal dimerization modulates the function of this GT.

Autor: Sharma Y; CSIR-Institute of Microbial Technology, Chandigarh, India., Ahlawat S; CSIR-Institute of Microbial Technology, Chandigarh, India.; Academy of Scientific and Innovation Research (AcSIR), Ghaziabad, India., Ashish; CSIR-Institute of Microbial Technology, Chandigarh, India.; Academy of Scientific and Innovation Research (AcSIR), Ghaziabad, India., Rao A; CSIR-Institute of Microbial Technology, Chandigarh, India.; Academy of Scientific and Innovation Research (AcSIR), Ghaziabad, India.
Jazyk: angličtina
Zdroj: Journal of biomolecular structure & dynamics [J Biomol Struct Dyn] 2023 Sep 15, pp. 1-15. Date of Electronic Publication: 2023 Sep 15.
DOI: 10.1080/07391102.2023.2255906
Abstrakt: Here, we describe hitherto unknown shape-function of S/O-HexNActransferase SvGT (ORF AQF52_3101) instrumental in glycosylation of bacteriocin SvC (ORF AQF52_3099) in Streptomyces venezuelae ATCC 15439. Data from gel filtration, mass spectrometry, analytical ultracentrifugation, and Small Angle X-ray Scattering (SAXS), experiments confirmed elongated dimeric shape in solution for SvGT protein. Enzyme assays confirmed the dependence of SvGT on the availability of Mg 2+ ions to be functionally activated. SAXS data analysis provided that apo and Mg 2+ -activated protein adopt a shape characterized by a radius of gyration and maximum linear dimension of 5.2 and 17.0 nm, and 5.3 and 17.8 nm, respectively. Alphafold2 server was used to model the monomeric chain of this protein which was docked on self to obtain different poses of the dimeric entity. Experimental SAXS data was used to select and refine the structure of SvGT dimer. Results showed that Mg 2+ ions induce reorientation of the GT domain of one chain leading to a dimer with C2 symmetry, and the C-terminal portion entangles with each other in all states. Mutation-rendered alteration in activity profiles confirmed the role of conserved residues around catalytic motif. Global structure analysis puts forth the need to understand the role of constitutionally diverse C-terminal portion in regulating substrate selectivity.Communicated by Ramaswamy H. Sarma.
Databáze: MEDLINE