1lba
|
THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE
OverviewOverview
The lysozyme of bacteriophage T7 is a bifunctional protein that cuts amide, bonds in the bacterial cell wall and binds to and inhibits transcription, by T7 RNA polymerase. The structure of a mutant T7 lysozyme has been, determined by x-ray crystallography and refined at 2.2-A resolution. The, protein folds into an alpha/beta-sheet structure that has a prominent, cleft. A zinc atom is located in the cleft, bound directly to three amino, acids and, through a water molecule, to a fourth. Zinc is required for, amidase activity but not for inhibition of T7 RNA polymerase. Alignment of, the zinc ligands of T7 lysozyme with those of carboxypeptidase A and, thermolysin suggests structural similarity among the catalytic sites for, the amidase and these zinc proteases. Mutational analysis identified, presumed catalytic residues for amidase activity within the cleft and a, surface that appears to be the site of binding to T7 RNA polymerase., Binding of T7 RNA polymerase inhibits amidase activity.
About this StructureAbout this Structure
1LBA is a Single protein structure of sequence from Bacteriophage t7 with ZN as ligand. Active as N-acetylmuramoyl-L-alanine amidase, with EC number 3.5.1.28 Full crystallographic information is available from OCA.
ReferenceReference
The structure of bacteriophage T7 lysozyme, a zinc amidase and an inhibitor of T7 RNA polymerase., Cheng X, Zhang X, Pflugrath JW, Studier FW, Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):4034-8. PMID:8171031
Page seeded by OCA on Tue Nov 20 20:26:33 2007