1Z6R

Crystal structure of Mlc from Escherichia coli

1Z6R の概要

• エントリーDOI: 10.2210/pdb1z6r/pdb
• 分子名称: Mlc protein, ZINC ION (2 entities in total)
• 機能のキーワード: transcriptional repressor, rok family protein, dna binding protein, helix-turn-helix, phosphotransferase system, metalloprotein, transcription
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 179525.00

構造登録者

Schiefner, A.,Gerber, K.,Seitz, S.,Welte, W.,Diederichs, K.,Boos, W. (登録日: 2005-03-23, 公開日: 2005-06-14, 最終更新日: 2024-10-16)

主引用文献

Schiefner, A.,Gerber, K.,Seitz, S.,Welte, W.,Diederichs, K.,Boos, W.
The crystal structure of Mlc, a global regulator of sugar metabolism in Escherichia coli
J.Biol.Chem., 280:29073-29079, 2005

PubMed Abstract: Mlc from Escherichia coli is a transcriptional repressor controlling the expression of a number of genes encoding enzymes of the phosphotransferase system (PTS), including ptsG and manXYZ, the specific enzyme II for glucose and mannose PTS transporters. In addition, Mlc controls the transcription of malT, the gene of the global activator of the mal regulon. The inactivation of Mlc as a repressor is mediated by binding to an actively transporting PtsG (EIICB(Glc)). Here we report the crystal structure of Mlc at 2.7 A resolution representing the first described structure of an ROK (repressors, open reading frames, and kinases) family protein. Mlc forms stable dimers thus explaining its binding affinity to palindromic operator sites. The N-terminal helix-turn-helix domain of Mlc is stabilized by the amphipathic C-terminal helix implicated earlier in EIICB(Glc) binding. Furthermore, the structure revealed a metal-binding site within the cysteine-rich ROK consensus motif that coordinates a structurally important zinc ion. A strongly reduced repressor activity was observed when two of the zinc-coordinating cysteine residues were exchanged against serine or alanine, demonstrating the role of zinc in Mlc-mediated repressor function. The structures of a putative fructokinase from Bacillus subtilis, the glucokinase from Escherichia coli, and a glucomannokinase from Arthrobacter sp. showed high structural homology to the ROK family part of Mlc.

PubMed: 15929984
DOI: 10.1074/jbc.M504215200

実験手法

X-RAY DIFFRACTION (2.7 Å)