Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
2004-8-2
pubmed:abstractText
The sodC-encoded Mycobacterium tuberculosis superoxide dismutase (SOD) shows high sequence homology to other members of the copper/zinc-containing SOD family. Its three-dimensional structure is reported here, solved by x-ray crystallography at 1.63-A resolution. Metal analyses of the recombinant protein indicate that the native form of the enzyme lacks the zinc ion, which has a very important structural and functional role in all other known enzymes of this class. The absence of zinc within the active site is due to significant rearrangements in the zinc subloop, including deletion or mutation of the metal ligands His115 and His123. Nonetheless, the enzyme has a catalytic rate close to the diffusion limit; and unlike all other copper/zinc-containing SODs devoid of zinc, the geometry of the copper site is pH-independent. The protein shows a novel dimer interface characterized by a long and rigid loop, which confers structural stability to the enzyme. As the survival of bacterial pathogens within their host critically depends on their ability to recruit zinc in highly competitive environments, we propose that the observed structural rearrangements are required to build up a zinc-independent but fully active and stable copper-containing SOD.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33447-55
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15155722-Amino Acid Sequence, pubmed-meshheading:15155722-Binding Sites, pubmed-meshheading:15155722-Catalysis, pubmed-meshheading:15155722-Copper, pubmed-meshheading:15155722-Crystallization, pubmed-meshheading:15155722-Crystallography, X-Ray, pubmed-meshheading:15155722-Dimerization, pubmed-meshheading:15155722-Electron Spin Resonance Spectroscopy, pubmed-meshheading:15155722-Escherichia coli, pubmed-meshheading:15155722-Hydrogen-Ion Concentration, pubmed-meshheading:15155722-Kinetics, pubmed-meshheading:15155722-Models, Molecular, pubmed-meshheading:15155722-Molecular Sequence Data, pubmed-meshheading:15155722-Molecular Structure, pubmed-meshheading:15155722-Mycobacterium tuberculosis, pubmed-meshheading:15155722-Recombinant Proteins, pubmed-meshheading:15155722-Sequence Alignment, pubmed-meshheading:15155722-Static Electricity, pubmed-meshheading:15155722-Superoxide Dismutase, pubmed-meshheading:15155722-Zinc
pubmed:year
2004
pubmed:articleTitle
Unique features of the sodC-encoded superoxide dismutase from Mycobacterium tuberculosis, a fully functional copper-containing enzyme lacking zinc in the active site.
pubmed:affiliation
Structural Biology Laboratory, ELETTRA, Sincrotrone Trieste, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't