1ID8

NMR STRUCTURE OF GLUTAMATE MUTASE (B12-BINDING SUBUNIT) COMPLEXED WITH THE VITAMIN B12 NUCLEOTIDE

1ID8 の概要

• エントリーDOI: 10.2210/pdb1id8/pdb
• 関連するPDBエントリー: 1CB7 1FMF
• 分子名称: METHYLASPARTATE MUTASE S CHAIN, 2-HYDROXY-PROPYL-AMMONIUM, PHOSPHORIC ACID MONO-[5-(5,6-DIMETHYL-BENZOIMIDAZOL-1-YL)-4-HYDROXY-2-HYDROXYMETHYL-TETRAHYDRO-FURAN-3-YL] ESTER (3 entities in total)
• 機能のキーワード: coenzyme b12, ligand binding, nucleotide, protein nmr spectroscopy, protein folding, isomerase
• 由来する生物種: Clostridium tetanomorphum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 15198.26

構造登録者

Tollinger, M.,Eichmuller, C.,Konrat, R.,Huhta, M.S.,Marsh, E.N.G.,Krautler, B. (登録日: 2001-04-04, 公開日: 2001-06-27, 最終更新日: 2024-05-22)

主引用文献

Tollinger, M.,Eichmuller, C.,Konrat, R.,Huhta, M.S.,Marsh, E.N.,Krautler, B.
The B(12)-binding subunit of glutamate mutase from Clostridium tetanomorphum traps the nucleotide moiety of coenzyme B(12).
J.Mol.Biol., 309:777-791, 2001

PubMed Abstract: Glutamate mutase from Clostridium tetanomorphum binds coenzyme B(12) in a base-off/His-on form, in which the nitrogenous ligand of the B(12)-nucleotide function is displaced from cobalt by a conserved histidine. The effect of binding the B(12)-nucleotide moiety to MutS, the B(12)-binding subunit of glutamate mutase, was investigated using NMR spectroscopic methods. Binding of the B(12)-nucleotide to MutS was determined to occur with K(d)=5.6(+/-0.7) mM and to be accompanied by a specific conformational change in the protein. The nucleotide binding cleft of the apo-protein, which is formed by a dynamic segment with propensity for partial alpha-helical conformation (the "nascent" alpha-helix), becomes completely structured upon binding of the B(12)-nucleotide, with formation of helix alpha1. In contrast, the segment containing the conserved residues of the B(12)-binding Asp-x-His-x-x-Gly motif remains highly dynamic in the protein/B(12)-nucleotide complex. From relaxation studies, the time constant tau, which characterizes the time scale for the formation of helix alpha1, was estimated to be about 30 micros (15)N and was the same in both, apo-protein and nucleotide-bound protein. Thus, the binding of the B(12)-nucleotide moiety does not significantly alter the kinetics of helix formation, but only shifts the equilibrium towards the structured fold. These results indicate MutS to be structured in such a way, as to be able to trap the nucleotide segment of the base-off form of coenzyme B(12) and provide, accordingly, the first structural clues as to how the process of B(12)-binding occurs.

PubMed: 11397096
DOI: 10.1006/jmbi.2001.4696

実験手法

SOLUTION NMR