1KEB

Crystal Structure of Double Mutant M37L,P40S E.coli Thioredoxin

1KEB の概要

• エントリーDOI: 10.2210/pdb1keb/pdb
• 分子名称: Thioredoxin 1, COPPER (II) ION (3 entities in total)
• 機能のキーワード: thioredoxin fold, proline, alpha-helix, electron transport
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 23445.72

構造登録者

Rudresh,Jain, R.,Dani, V.,Mitra, A.,Srivastava, S.,Sarma, S.P.,Varadarajan, R.,Ramakumar, S. (登録日: 2001-11-15, 公開日: 2002-11-13, 最終更新日: 2024-11-13)

主引用文献

Rudresh,Jain, R.,Dani, V.,Mitra, A.,Srivastava, S.,Sarma, S.P.,Varadarajan, R.,Ramakumar, S.
Structural Consequences of Replacement of an alpha-helical Pro Residue in E.coli Thioredoxin
PROTEIN ENG., 15:627-633, 2002

PubMed Abstract: While it is well known that introduction of Pro residues into the interior of protein alpha-helices is destabilizing, there have been few studies that have examined the structural and thermodynamic effects of the replacement of a Pro residue in the interior of a protein alpha-helix. We have previously reported an increase in stability in the P40S mutant of Escherichia coli thioredoxin of 1-1.5 kcal/mol in the temperature range 280-330 K. This paper describes the structure of the P40S mutant at a resolution of 1.8 A. In wild-type thioredoxin, P40 is located in the interior of helix two, a long alpha-helix that extends from residues 32 to 49 with a kink at residue 40. Structural differences between the wild-type and P40S are largely localized to the above helix. In the P40S mutant, there is an expected additional hydrogen bond formed between the amide of S40 and the carbonyl of residue K36 and also additional hydrogen bonds between the side chain of S40 and the carbonyl of K36. The helix remains kinked. In the wild-type, main chain hydrogen bonds exist between the amide of 44 and carbonyl of 40 and between the amide of 43 and carbonyl of 39. However, these are absent in P40S. Instead, these main chain atoms are hydrogen bonded to water molecules. The increased stability of P40S is likely to be due to the net increase in the number of hydrogen bonds in helix two of E.coli thioredoxin.

PubMed: 12364576
DOI: 10.1093/protein/15.8.627

実験手法

X-RAY DIFFRACTION (1.8 Å)