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Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.

IR@CFTRI: CSIR-Central Food Technological Research Institute, Mysore

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Relation http://ir.cftri.com/13595/
https://doi.org/10.1016/j.str.2018.02.002
 
Title Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.
 
Creator Neha, Vithani
Pravin Kumar, A. J.
Sunil Kumar, Verma
Ravi, Tripathi
Shalini, A.
Nishanth, N. Nair
Balaji, Prakash
 
Subject 31 Sugar Chemistry
 
Description The nucleotidyl transfer reaction, catalyzed by sugar nucleotidyltransferases (SNTs), is assisted by two active site Mg2+ ions. While studying this reaction using X-ray crystallography, we captured snapshots of the pyrophosphate (product) as it exits along a pocket. Surprisingly, one of the active site Mg2+ ions remains coordinated to the exiting pyrophosphate. This hints at the participation of Mg2+ in the process of product release, besides its role in catalyzing nucleotidyl transfer. These observations are further supported by enhanced sampling molecular dynamics simulations. Free energy computations suggest that the product release is likely to be rate limiting in SNTs, and the origin of the high free energy barrier for product release could be traced back to the ‘‘slow’’ conformational change of an Arg residue at the exit end of the pocket. These results establish a dual role for Mg2+, and propose a general mechanism of product release during the nucleotidyl transfer by SNTs.
 
Date 2018
 
Type Article
PeerReviewed
 
Format pdf
 
Language en
 
Identifier http://ir.cftri.com/13595/1/Structure%2026%2C%20459%E2%80%93466%202018.pdf
Neha, Vithani and Pravin Kumar, A. J. and Sunil Kumar, Verma and Ravi, Tripathi and Shalini, A. and Nishanth, N. Nair and Balaji, Prakash (2018) Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases. Structure, 26. pp. 459-466.