Joe Granger Methionine Repressor: Escherichia coli

From Proteopedia

Revision as of 01:23, 8 November 2012

spinqualitylabelsall models PDB ID 1cma Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
1cma, resolution 2.80Å ()
Ligands:
Structural annotation: Resources: CATH : 1Cmaa00, 1Cmab00 InterPro : Ipr010985, Ipr002084 Pfam : PF01340 SCOP : d1cmaa_, d1cmab_ UniProt : P0A8U6
Functional annotation: Cellular component: cytoplasm Biological process: methionine metabolic process amino acid biosynthetic process negative regulation of transcription, DNA-dependent transcription regulation of transcription, DNA-dependent regulation of transcription methionine biosynthetic process Molecular function: DNA binding transcription repressor activity transcription factor activity
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

MET REPRESSOR/DNA COMPLEX + S-ADENOSYL-METHIONINE

{{ The Met Repressor Protein is involved with regulating the synthesis of methionine. This protein works to bind the DNA operatiors that activate the transcription of genes that produce methionine. When this protein is bound to DNA, it prevents RNA polymeraseII from binding and promoting transcription. The crystal structure of the met repressor-operator complex shows two dimeric repressor molecules bound to adjacent sites 8 base pairs apart on an 18-base-pair DNA fragment. The is bound tightly with The DNA operator in the major groove. What binds the to the DNA tightly is the two Beta sheets. While they are both from differnt monomers, they complex in an anti parrell fashion . Sequence specificity is achieved by insertion of double-stranded antiparallel protein beta-ribbons into the major groove of B-form DNA, with direct hydrogen-bonding between amino-acid side chains and the base pairs. The repressor also recognizes sequence-dependent distortion or flexibility of the operator phosphate backbone, conferring specificity even for inaccessible base pairs. }}

About this Structure

1cma is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

• Somers WS, Phillips SE. Crystal structure of the met repressor-operator complex at 2.8 A resolution reveals DNA recognition by beta-strands. Nature. 1992 Oct 1;359(6394):387-93. PMID:1406951 doi:http://dx.doi.org/10.1038/359387a0

Santanu Maitra, and james S. Nowick. (2000) B-Sheet Interactions Between Proteins. University of Califonia Irvine. 15