1ibt: Difference between revisions
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|PDB= 1ibt |SIZE=350|CAPTION= <scene name='initialview01'>1ibt</scene>, resolution 2.6Å | |PDB= 1ibt |SIZE=350|CAPTION= <scene name='initialview01'>1ibt</scene>, resolution 2.6Å | ||
|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= <scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene> | ||
|ACTIVITY= [http://en.wikipedia.org/wiki/Histidine_decarboxylase Histidine decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.22 4.1.1.22] | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Histidine_decarboxylase Histidine decarboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.22 4.1.1.22] </span> | ||
|GENE= HDCA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1591 Lactobacillus sp.]) | |GENE= HDCA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1591 Lactobacillus sp.]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1pya|1PYA]], [[1hq6|1HQ6]], [[1ibu|1IBU]], [[1ibv|1IBV]], [[1ibw|1IBW]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ibt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ibt OCA], [http://www.ebi.ac.uk/pdbsum/1ibt PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ibt RCSB]</span> | |||
}} | }} | ||
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[[Category: site-directed mutant]] | [[Category: site-directed mutant]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:17:35 2008'' | ||
Revision as of 21:17, 30 March 2008
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| , resolution 2.6Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | HDCA (Lactobacillus sp.) | ||||||
| Activity: | Histidine decarboxylase, with EC number 4.1.1.22 | ||||||
| Related: | 1PYA, 1HQ6, 1IBU, 1IBV, 1IBW
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STRUCTURE OF THE D53,54N MUTANT OF HISTIDINE DECARBOXYLASE AT-170 C
OverviewOverview
Histidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth. HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH. The X-ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate-binding site. The HDC trimer has also been shown to exhibit cooperative kinetics at neutral pH, that is, histidine can trigger a T-state to R-state transition. The D53,54N mutant of HDC has an elevated Km, even at low pH, indicating that the enzyme assumes the low activity T-state. We have solved the structures of the D53,54N mutant at low pH, with and without the substrate analog histidine methyl ester (HME) bound. Structural analysis shows that the apo-D53,54N mutant is in the inactive or T-state and that binding of the substrate analog induces the enzyme to adopt the active or R-state. A mechanism for the cooperative transition is proposed.
About this StructureAbout this Structure
1IBT is a Protein complex structure of sequences from Lactobacillus sp.. Full crystallographic information is available from OCA.
ReferenceReference
Structure and cooperativity of a T-state mutant of histidine decarboxylase from Lactobacillus 30a., Worley S, Schelp E, Monzingo AF, Ernst S, Robertus JD, Proteins. 2002 Feb 15;46(3):321-9. PMID:11835507
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