Linked Life Data

12486720

Source:http://linkedlifedata.com/resource/pubmed/id/12486720

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-12-17
pubmed:abstractText
Heme catalases are homotetrameric enzymes with a highly conserved complex quaternary structure, and their functional role is still not well understood. Proteus mirabilis catalase (PMC), a heme enzyme belonging to the family of NADPH-binding catalases, was efficiently overexpressed in E. coli. The recombinant catalase (rec PMC) was deficient in heme with one-third heme and two-thirds protoporphyrin IX as determined by mass spectrometry and chemical methods. This ratio was influenced by the expression conditions, but the enzyme-specific activity calculated relative to the heme content remained unchanged. The crystal structure of rec PMC was solved to a resolution of 2.0 A, the highest resolution obtained to date with PMC. The overall structure was quite similar to that of wild-type PMC, and it is surprising that the absence of iron had no effect on the structure of the active site. Met 53 close to the essential His 54 was found less oxidized in rec PMC than in the wild-type enzyme. An acetate anion was modeled in an anionic pocket, away from the heme group but important for the enzymatic reaction. An alternate conformation observed for Arg 99 could play a role in the formation of the H-bond network connecting two symmetrical subunits of the tetramer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1097-0134
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley-Liss, Inc.
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
261-71
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
High-resolution structure and biochemical properties of a recombinant Proteus mirabilis catalase depleted in iron.
pubmed:affiliation
Institut de Biologie Structurale Jean-Pierre Ebel, CEA/CNRS/UJF, UMR 5075, Grenoble cedex 1, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't