1Z6R
Crystal structure of Mlc from Escherichia coli
Summary for 1Z6R
| Entry DOI | 10.2210/pdb1z6r/pdb |
| Descriptor | Mlc protein, ZINC ION (2 entities in total) |
| Functional Keywords | transcriptional repressor, rok family protein, dna binding protein, helix-turn-helix, phosphotransferase system, metalloprotein, transcription |
| Biological source | Escherichia coli |
| Total number of polymer chains | 4 |
| Total formula weight | 179525.00 |
| Authors | Schiefner, A.,Gerber, K.,Seitz, S.,Welte, W.,Diederichs, K.,Boos, W. (deposition date: 2005-03-23, release date: 2005-06-14, Last modification date: 2024-10-16) |
| Primary citation | 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 Cited by 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: 15929984DOI: 10.1074/jbc.M504215200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.7 Å) |
Structure validation
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