6CKK

N. meningitidis CMP-sialic acid synthetase in the presence of CTP and Ca2+

6CKK の概要

• エントリーDOI: 10.2210/pdb6ckk/pdb
• 分子名称: N-acylneuraminate cytidylyltransferase, CYTIDINE-5'-TRIPHOSPHATE, CALCIUM ION, ... (4 entities in total)
• 機能のキーワード: polysaccharide synthesis, sialic acid-activator, cmp-transferase, transferase
• 由来する生物種: Neisseria meningitidis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 50927.36

構造登録者

Matthews, M.M.,Fisher, A.J.,Chen, X. (登録日: 2018-02-28, 公開日: 2019-03-06, 最終更新日: 2023-10-04)

主引用文献

Matthews, M.M.,McArthur, J.B.,Li, Y.,Yu, H.,Chen, X.,Fisher, A.J.
Catalytic Cycle ofNeisseria meningitidisCMP-Sialic Acid Synthetase Illustrated by High-Resolution Protein Crystallography.
Biochemistry, 2019

PubMed Abstract: Cytidine 5'-monophosphate (CMP)-sialic acid synthetase (CSS) is an essential enzyme involved in the biosynthesis of carbohydrates and glycoconjugates containing sialic acids, a class of α-keto acids that are generally terminal key recognition residues by many proteins that play important biological and pathological roles. The CSS from (NmCSS) has been commonly used with other enzymes such as sialic acid aldolase and/or sialyltransferase in synthesizing a diverse array of compounds containing sialic acid or its naturally occurring and non-natural derivatives. To better understand its catalytic mechanism and substrate promiscuity, four NmCSS crystal structures trapped at various stages of the catalytic cycle with bound substrates, substrate analogues, and products have been obtained and are presented here. These structures suggest a mechanism for an "open" and "closed" conformational transition that occurs as sialic acid binds to the NmCSS/cytidine-5'-triphosphate (CTP) complex. The closed conformation positions critical residues to help facilitate the nucleophilic attack of sialic acid C2-OH to the α-phosphate of CTP, which is also aided by two observed divalent cations. Product formation drives the active site opening, promoting the release of products.

PubMed: 31583886
DOI: 10.1021/acs.biochem.9b00517

実験手法

X-RAY DIFFRACTION (1.8 Å)