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[[Image:1lba.gif|left|200px]]<br /><applet load="1lba" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1lba, resolution 2.2&Aring;" />
'''THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE'''<br />


==Overview==
==THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE==
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.
<StructureSection load='1lba' size='340' side='right'caption='[[1lba]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1lba]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_phage_T7 Escherichia phage T7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LBA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LBA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1lba FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lba OCA], [https://pdbe.org/1lba PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lba RCSB], [https://www.ebi.ac.uk/pdbsum/1lba PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lba ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ENLYS_BPT7 ENLYS_BPT7] Plays an important role in the switch between viral transcription and T7 genome replication. Once produced in sufficient amount, interacts with and inhibits T7 RNA polymerase that becomes unable to produce additional transcripts. This lysozyme-polymerase complex in turn plays an active role in T7 genome replication and packaging.  Endolysin with amidase activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and breaking down the peptidoglycan layer.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lb/1lba_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1lba ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
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].
*[[Lysozyme 3D structures|Lysozyme 3D structures]]
 
__TOC__
==Reference==
</StructureSection>
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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8171031 8171031]
[[Category: Escherichia phage T7]]
[[Category: Bacteriophage t7]]
[[Category: Large Structures]]
[[Category: N-acetylmuramoyl-L-alanine amidase]]
[[Category: Cheng X]]
[[Category: Single protein]]
[[Category: Cheng, X.]]
[[Category: ZN]]
[[Category: hydrolase(acting on linear amides)]]
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:22 2008''

Latest revision as of 10:31, 14 February 2024

THE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASETHE STRUCTURE OF BACTERIOPHAGE T7 LYSOZYME, A ZINC AMIDASE AND AN INHIBITOR OF T7 RNA POLYMERASE

Structural highlights

1lba is a 1 chain structure with sequence from Escherichia phage T7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.2Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

ENLYS_BPT7 Plays an important role in the switch between viral transcription and T7 genome replication. Once produced in sufficient amount, interacts with and inhibits T7 RNA polymerase that becomes unable to produce additional transcripts. This lysozyme-polymerase complex in turn plays an active role in T7 genome replication and packaging. Endolysin with amidase activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and breaking down the peptidoglycan layer.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

1lba, resolution 2.20Å

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