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1lba
From Proteopedia
(New page: 200px<br /><applet load="1lba" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lba, resolution 2.2Å" /> '''THE STRUCTURE OF BACT...) |
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| - | [[Image:1lba.gif|left|200px]]<br /><applet load="1lba" size=" | + | [[Image:1lba.gif|left|200px]]<br /><applet load="1lba" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1lba, resolution 2.2Å" /> | caption="1lba, resolution 2.2Å" /> | ||
'''THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE'''<br /> | '''THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The lysozyme of bacteriophage T7 is a bifunctional protein that cuts amide | + | 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 Structure== | ==About this Structure== | ||
| - | 1LBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/N-acetylmuramoyl-L-alanine_amidase N-acetylmuramoyl-L-alanine amidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.28 3.5.1.28] Full crystallographic information is available from [http:// | + | 1LBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t7 Bacteriophage t7] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/N-acetylmuramoyl-L-alanine_amidase N-acetylmuramoyl-L-alanine amidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.28 3.5.1.28] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LBA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: hydrolase(acting on linear amides)]] | [[Category: hydrolase(acting on linear amides)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:22 2008'' |
Revision as of 11:43, 21 February 2008
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THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE
Overview
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 Structure
1LBA is a Single protein structure of sequence from Bacteriophage t7 with as ligand. Active as N-acetylmuramoyl-L-alanine amidase, with EC number 3.5.1.28 Full crystallographic information is available from OCA.
Reference
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
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