1ngk: Difference between revisions
No edit summary |
No edit summary |
||
| (10 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
< | ==Crystallographic Structure of Mycobacterium tuberculosis Hemoglobin O== | ||
<StructureSection load='1ngk' size='340' side='right'caption='[[1ngk]], [[Resolution|resolution]] 2.11Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1ngk]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NGK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NGK 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]] 2.11Å</td></tr> | |||
- | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYN:CYANIDE+ION'>CYN</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1ngk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ngk OCA], [https://pdbe.org/1ngk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ngk RCSB], [https://www.ebi.ac.uk/pdbsum/1ngk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ngk ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/TRHBO_MYCTU TRHBO_MYCTU] When expressed in E.coli and M.smegmatis, HbO increases oxygen uptake. Membrane vesicles of E.coli carrying HbO show a respiration activity about twice that of membranes without HbO. HbO seems to interact with a terminal oxidase. Therefore, HbO could participate in oxygen/electron-transfer process, suggesting a function related to the facilitation of oxygen transfer during aerobic metabolism of M.tuberculosis. | |||
== 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/ng/1ngk_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1ngk ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Truncated hemoglobins (Hbs) are small hemoproteins, identified in microorganisms and in some plants, forming a separate cluster within the Hb superfamily. Two distantly related truncated Hbs, trHbN and trHbO, are expressed at different developmental stages in Mycobacterium tuberculosis. Sequence analysis shows that the two proteins share 18% amino acid identities and belong to different groups within the truncated Hb cluster. Although a specific defense role against nitrosative stress has been ascribed to trHbN (expressed during the Mycobacterium stationary phase), no clear functions have been recognized for trHbO, which is expressed throughout the Mycobacterium growth phase. The 2.1-A crystal structure of M. tuberculosis cyano-met trHbO shows that the protein assembles in a compact dodecamer. Six of the dodecamer subunits are characterized by a double conformation for their CD regions and, most notably, by a covalent bond linking the phenolic O atom of TyrB10 to the aromatic ring of TyrCD1, in the heme distal cavity. All 12 subunits display a cyanide ion bound to the heme Fe atom, stabilized by a tight hydrogen-bonded network based on the (globin very rare) TyrCD1 and TrpG8 residues. The small apolar AlaE7 residue leaves room for ligand access to the heme distal site through the conventional "E7 path," as proposed for myoglobin. Different from trHbN, where a 20-A protein matrix tunnel is held to sustain ligand diffusion to an otherwise inaccessible heme distal site, the topologically related region in trHbO hosts two protein matrix cavities. | |||
A TyrCD1/TrpG8 hydrogen bond network and a TyrB10TyrCD1 covalent link shape the heme distal site of Mycobacterium tuberculosis hemoglobin O.,Milani M, Savard PY, Ouellet H, Ascenzi P, Guertin M, Bolognesi M Proc Natl Acad Sci U S A. 2003 May 13;100(10):5766-71. Epub 2003 Apr 28. PMID:12719529<ref>PMID:12719529</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1ngk" style="background-color:#fffaf0;"></div> | |||
== References == | |||
--> | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
[[Category: Mycobacterium tuberculosis]] | [[Category: Mycobacterium tuberculosis]] | ||
[[Category: Ascenzi P]] | |||
[[Category: Ascenzi | [[Category: Bolognesi M]] | ||
[[Category: Bolognesi | [[Category: Guertin M]] | ||
[[Category: Guertin | [[Category: Milani M]] | ||
[[Category: Milani | [[Category: Oullet H]] | ||
[[Category: Oullet | [[Category: Savard P-Y]] | ||
[[Category: Savard | |||
Latest revision as of 03:17, 21 November 2024
Crystallographic Structure of Mycobacterium tuberculosis Hemoglobin OCrystallographic Structure of Mycobacterium tuberculosis Hemoglobin O
Structural highlights
FunctionTRHBO_MYCTU When expressed in E.coli and M.smegmatis, HbO increases oxygen uptake. Membrane vesicles of E.coli carrying HbO show a respiration activity about twice that of membranes without HbO. HbO seems to interact with a terminal oxidase. Therefore, HbO could participate in oxygen/electron-transfer process, suggesting a function related to the facilitation of oxygen transfer during aerobic metabolism of M.tuberculosis. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTruncated hemoglobins (Hbs) are small hemoproteins, identified in microorganisms and in some plants, forming a separate cluster within the Hb superfamily. Two distantly related truncated Hbs, trHbN and trHbO, are expressed at different developmental stages in Mycobacterium tuberculosis. Sequence analysis shows that the two proteins share 18% amino acid identities and belong to different groups within the truncated Hb cluster. Although a specific defense role against nitrosative stress has been ascribed to trHbN (expressed during the Mycobacterium stationary phase), no clear functions have been recognized for trHbO, which is expressed throughout the Mycobacterium growth phase. The 2.1-A crystal structure of M. tuberculosis cyano-met trHbO shows that the protein assembles in a compact dodecamer. Six of the dodecamer subunits are characterized by a double conformation for their CD regions and, most notably, by a covalent bond linking the phenolic O atom of TyrB10 to the aromatic ring of TyrCD1, in the heme distal cavity. All 12 subunits display a cyanide ion bound to the heme Fe atom, stabilized by a tight hydrogen-bonded network based on the (globin very rare) TyrCD1 and TrpG8 residues. The small apolar AlaE7 residue leaves room for ligand access to the heme distal site through the conventional "E7 path," as proposed for myoglobin. Different from trHbN, where a 20-A protein matrix tunnel is held to sustain ligand diffusion to an otherwise inaccessible heme distal site, the topologically related region in trHbO hosts two protein matrix cavities. A TyrCD1/TrpG8 hydrogen bond network and a TyrB10TyrCD1 covalent link shape the heme distal site of Mycobacterium tuberculosis hemoglobin O.,Milani M, Savard PY, Ouellet H, Ascenzi P, Guertin M, Bolognesi M Proc Natl Acad Sci U S A. 2003 May 13;100(10):5766-71. Epub 2003 Apr 28. PMID:12719529[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
| ||||||||||||||||||