We have located links that may give you full text access.
HDX-MS Reveals Substrate-Dependent, Localized EX1 Conformational Dynamics in the Retaining GT-B Glycosyltransferase, MshA.
Biochemistry 2023 August 18
Glycosyltransferases (GTs) are well-characterized with respect to static 3D structures and molecular dynamics simulations, but there is a lack of reports on in-solution dynamics on time scales relevant to turnover. Here, backbone amide hydrogen/deuterium exchange followed by mass spectrometry (HDX-MS) was used to investigate the in-solution dynamics of the model retaining GT MshA from Corynebacterium glutamicum (CgMshA). CgMshA has a GT-B fold and catalyzes the transfer of N -acetyl-glucosamine (GlcNAc) from UDP-GlcNAc to l- myo -inositol-1-phosphate in the first step in mycothiol biosynthesis. HDX-MS results identify several key regions of conformational changes in response to UDP-GlcNAc binding, including residues 159-198 in the N-terminal domain and residues 323-354 in the C-terminal domain. These regions also exhibited substrate-dependent EX1 exchange kinetics consistent with conformational tension on the milliseconds to seconds time scale. A potential source of this conformational change is the flexible β4/α5 loop in the C-terminal domain, which sits at the interface of the two domains and likely interacts with the GlcNAc ring of UDP-GlcNAc. In contrast to UDP-GlcNAc, the UDP-CgMshA product complex exhibited severe decreases in deuterium incorporation, suggesting a less dynamic conformation. The HDX-MS results are complemented by solvent viscosity effects of 1.8-2.3 on the CgMshA k cat value, which are consistent with product release as a rate-determining step and possibly a direct role for protein dynamics in catalysis. The identification of in-solution dynamics that are sensitive to substrate binding allows for the proposal of a more detailed mechanism in CgMshA including conformation tension between the donor sugar and the flexible C-terminal domain β4/α5 loop providing sufficient conformational sampling for substrate-assisted catalysis to occur.
Full text links
Related Resources
Trending Papers
A Guide to the Use of Vasopressors and Inotropes for Patients in Shock.Journal of Intensive Care Medicine 2024 April 14
Prevention and treatment of ischaemic and haemorrhagic stroke in people with diabetes mellitus: a focus on glucose control and comorbidities.Diabetologia 2024 April 17
British Society for Rheumatology guideline on management of adult and juvenile onset Sjögren disease.Rheumatology 2024 April 17
Diagnosis and Management of Cardiac Sarcoidosis: A Scientific Statement From the American Heart Association.Circulation 2024 April 19
Albumin: a comprehensive review and practical guideline for clinical use.European Journal of Clinical Pharmacology 2024 April 13
Eosinophilic Esophagitis: Clinical Pearls for Primary Care Providers and Gastroenterologists.Mayo Clinic Proceedings 2024 April
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app