Linked Life Data

19245529

Source:http://linkedlifedata.com/resource/pubmed/id/19245529

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2009-7-28
pubmed:abstractText
We report on the biochemical, phylogenetic and genetic regulation of PhoX, the major alkaline phosphatase protein from the soil bacterium Sinorhizobium meliloti. The protein is shown to be a member of a recently identified family of PhoX alkaline phosphatase proteins that is distinct from the well-characterized PhoA family. The mature S. meliloti PhoX protein is located in the periplasm and lacks a 76-amino-acid N-terminal Tat signal peptide. Its phosphatase activity was stimulated by Ca(+2) and was optimal at pH 9-11. Except for phytic acid and phosphatidic acid, the enzyme was active against a wide range of phosphorylated substrates (77 nucleotides, phosphorylated carbohydrates and amino acids) and thus exhibited low substrate specificity for C-O-P bonds. No C-P bond substrate was dephosphorylated while the protein was active with two of six phosphoramidate substrates (N-P bond) tested. Sinorhizobium meliloti phoX was induced when cells were starved for phosphorous and the induction was dependent on the PhoB-regulatory protein. We demonstrate by in vitro analysis that PhoB protein binds to two tandem 22 nt PhoB binding sites located 64-21 nt upstream from the phoX transcription start site. Analysis of 95 PhoX orthologues from diverse bacteria revealed two distinct phylogenetic groups of PhoX proteins. The two groups differed in having a conserved glycine (PhoX-I) or asparagine (PhoX-II) next to their putative catalytic Ca(+2) binding site. Analysis of the phoX promoter regions from many of these bacteria also revealed the presence of PhoB binding sites. Alkaline phosphatase proteins of either the PhoX or PhoA family (but rarely both) are found in many bacteria, thus it appears that these are functionally equivalent.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1462-2920
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1572-87
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Genetic and biochemical properties of an alkaline phosphatase PhoX family protein found in many bacteria.
pubmed:affiliation
Center for Environmental Genomics, Department of Biology, McMaster University, Hamilton, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't