1B8F

Histidine ammonia-lyase (HAL) from Pseudomonas putida

1B8F の概要

• エントリーDOI: 10.2210/pdb1b8f/pdb
• 分子名称: Histidine ammonia-lyase, SULFATE ION, GLYCEROL, ... (4 entities in total)
• 機能のキーワード: ammonia-lyase, histidine degradation, lyase
• 由来する生物種: Pseudomonas putida
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 53807.38

構造登録者

Schwede, T.F.,Schulz, G.E. (登録日: 1999-01-31, 公開日: 1999-05-06, 最終更新日: 2024-11-20)

主引用文献

Schwede, T.F.,Retey, J.,Schulz, G.E.
Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile.
Biochemistry, 38:5355-5361, 1999

PubMed Abstract: Histidine ammonia-lyase (EC 4.3.1.3) catalyzes the nonoxidative elimination of the alpha-amino group of histidine and is closely related to the important plant enzyme phenylalanine ammonia-lyase. The crystal structure of histidase from Pseudomonas putida was determined at 2.1 A resolution revealing a homotetramer with D2 symmetry, the molecular center of which is formed by 20 nearly parallel alpha-helices. The chain fold, but not the sequence, resembles those of fumarase C and related proteins. The structure shows that the reactive electrophile is a 4-methylidene-imidazole-5-one, which is formed autocatalytically by cyclization and dehydration of residues 142-144 with the sequence Ala-Ser-Gly. With respect to the first dehydration step, this modification resembles the chromophore of the green fluorescent protein. The active center is clearly established by the modification and by mutations. The observed geometry allowed us to model the bound substrate at a high confidence level. A reaction mechanism is proposed.

PubMed: 10220322
DOI: 10.1021/bi982929q

実験手法

X-RAY DIFFRACTION (2.1 Å)