The structure of bacteriophage T7 lysozyme, a zinc amidase and an inhibitor of T7 RNA polymerase

Cheng, X., Zhang, X., Pflugrath, J. W., Studier, F. W. (April 1994) The structure of bacteriophage T7 lysozyme, a zinc amidase and an inhibitor of T7 RNA polymerase. Proc Natl Acad Sci U S A, 91 (9). pp. 4034-8. ISSN 0027-8424 (Print)

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URL: http://www.ncbi.nlm.nih.gov/pubmed/8171031

Abstract

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.

Item Type: Paper
Uncontrolled Keywords: Amidohydrolases/metabolism/ ultrastructure Amino Acid Sequence Bacteriophage T7/ enzymology Binding Sites Comparative Study Crystallography, X-Ray DNA-Directed RNA Polymerases/ antagonists & inhibitors Metalloproteins/ultrastructure Molecular Sequence Data Muramidase/chemistry/metabolism/ ultrastructure Protein Structure, Tertiary Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. Structure-Activity Relationship Viral Proteins Zinc
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > RNA polymerase
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > bacteriophage
CSHL Authors:
Communities: CSHL labs
Depositing User: Matt Covey
Date: 26 April 1994
Date Deposited: 24 Jun 2015 20:50
Last Modified: 09 Nov 2017 19:40
PMCID: PMC43717
Related URLs:
URI: https://repository.cshl.edu/id/eprint/31466

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