1K98

AdoMet complex of MetH C-terminal fragment

1K98 の概要

• エントリーDOI: 10.2210/pdb1k98/pdb
• 関連するPDBエントリー: 1bmd 1k7y 1msk
• 分子名称: Methionine synthase, SULFATE ION, COBALAMIN (3 entities in total)
• 機能のキーワード: adomet binding, motion of 4-helix bundle, domain interactions, transferase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 66285.56

構造登録者

Bandarian, V.,Pattridge, K.A.,Lennon, B.W.,Huddler, D.P.,Matthews, R.G.,Ludwig, M.L. (登録日: 2001-10-27, 公開日: 2001-12-21, 最終更新日: 2023-08-16)

主引用文献

Bandarian, V.,Pattridge, K.A.,Lennon, B.W.,Huddler, D.P.,Matthews, R.G.,Ludwig, M.L.
Domain alternation switches B(12)-dependent methionine synthase to the activation conformation.
Nat.Struct.Biol., 9:53-56, 2002

PubMed Abstract: B(12)-dependent methionine synthase (MetH) from Escherichia coli is a large modular protein that uses bound cobalamin as an intermediate methyl carrier. Major domain rearrangements have been postulated to explain how cobalamin reacts with three different substrates: homocysteine, methyltetrahydrofolate and S-adenosylmethionine (AdoMet). Here we describe the 3.0 A structure of a 65 kDa C-terminal fragment of MetH that spans the cobalamin- and AdoMet-binding domains, arranged in a conformation suitable for the methyl transfer from AdoMet to cobalamin that occurs during activation. In the conversion to the activation conformation, a helical domain that capped the cofactor moves 26 A and rotates by 63 degrees, allowing formation of a new interface between cobalamin and the AdoMet-binding (activation) domain. Interactions with the MetH activation domain drive the cobalamin away from its binding domain in a way that requires dissociation of the axial cobalt ligand and, thereby, provide a mechanism for control of the distribution of enzyme conformations.

PubMed: 11731805
DOI: 10.1038/nsb738

実験手法

X-RAY DIFFRACTION (3.75 Å)