Human gut microbes express functionally distinct endoglycosidases to metabolize the same N-glycan substrate.

Autor: Sastre DE; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA. dsastre@emory.edu., Sultana N; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA.; Structural Biochemistry Unit, National Institute of Dental and Craniofacial Research (NIDCR/NIH), Bethesda, MD, USA., V A S Navarro M; Institute of Physics (IFSC-USP), University of São Paulo, São Carlos, SP, Brazil.; Center for Innovative Proteomics, Cornell University, Ithaca, NY, USA., Huliciak M; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA., Du J; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA.; Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia., Cifuente JO; Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain., Flowers M; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA., Liu X; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA., Lollar P; Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA., Trastoy B; Structural Glycoimmunology Laboratory, Biobizkaia Health Research Institute, Barakaldo, Bizkaia, Spain.; Ikerbasque, Basque Foundation for Science, Bilbao, Spain., Guerin ME; Structural Glycobiology Laboratory, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), Spanish National Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac 4-8, Tower R, Barcelona, Catalonia, Spain., Sundberg EJ; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA. eric.sundberg@emory.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Jun 15; Vol. 15 (1), pp. 5123. Date of Electronic Publication: 2024 Jun 15.
DOI: 10.1038/s41467-024-48802-3
Abstrakt: Bacteroidales (syn. Bacteroidetes) are prominent members of the human gastrointestinal ecosystem mainly due to their efficient glycan-degrading machinery, organized into gene clusters known as polysaccharide utilization loci (PULs). A single PUL was reported for catabolism of high-mannose (HM) N-glycan glyco-polypeptides in the gut symbiont Bacteroides thetaiotaomicron, encoding a surface endo-β-N-acetylglucosaminidase (ENGase), BT3987. Here, we discover an ENGase from the GH18 family in B. thetaiotaomicron, BT1285, encoded in a distinct PUL with its own repertoire of proteins for catabolism of the same HM N-glycan substrate as that of BT3987. We employ X-ray crystallography, electron microscopy, mass spectrometry-based activity measurements, alanine scanning mutagenesis and a broad range of biophysical methods to comprehensively define the molecular mechanism by which BT1285 recognizes and hydrolyzes HM N-glycans, revealing that the stabilities and activities of BT1285 and BT3987 were optimal in markedly different conditions. BT1285 exhibits significantly higher affinity and faster hydrolysis of poorly accessible HM N-glycans than does BT3987. We also find that two HM-processing endoglycosidases from the human gut-resident Alistipes finegoldii display condition-specific functional properties. Altogether, our data suggest that human gut microbes employ evolutionary strategies to express distinct ENGases in order to optimally metabolize the same N-glycan substrate in the gastroinstestinal tract.
(© 2024. The Author(s).)
Databáze: MEDLINE
Externí odkaz: