Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-3-31
pubmed:databankReference
pubmed:abstractText
Enzymes from organisms living in deep-sea are thought to have characteristic pressure-adaptation mechanisms in structure and function. To better understand these mechanisms in dihydrofolate reductase (DHFR), an essential enzyme in living cells, we cloned, overexpressed and purified four new DHFRs from the deep-sea bacteria Shewanella violacea (svDHFR), Photobacterium profundum (ppDHFR), Moritella yayanosii (myDHFR) and Moritella japonica (mjDHFR), and compared their structure and function with those of Escherichia coli DHFR (ecDHFR). These deep-sea DHFRs showed 33-56% primary structure identity to ecDHFR while far-ultraviolet circular dichroism and fluorescence spectra suggested that their secondary and tertiary structures were not largely different. The optimal temperature and pH for deep-sea DHFRs activity were lower than those of ecDHFR and different from each other. Deep-sea DHFRs kinetic parameters K(m) and k(cat) were larger than those of ecDHFR, resulting in 1.5-2.8-fold increase of k(cat)/K(m) except for mjDHFR which had a 28-fold decrease. The enzyme activity of ppDHFR and mjDHFR (moderate piezophilic bacteria) as well as ecDHFR decreased as pressure increased, while svDHFR and myDHFR (piezophilic bacteria) showed a significant tolerance to pressure. These results suggest that DHFRs from deep-sea bacteria possess specific enzymatic properties adapted to their life under high pressure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1756-2651
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
147
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
591-9
pubmed:meshHeading
pubmed-meshheading:20040594-Adaptation, Biological, pubmed-meshheading:20040594-Amino Acid Sequence, pubmed-meshheading:20040594-Atmospheric Pressure, pubmed-meshheading:20040594-Bacterial Proteins, pubmed-meshheading:20040594-Cloning, Molecular, pubmed-meshheading:20040594-Escherichia coli, pubmed-meshheading:20040594-Genes, Bacterial, pubmed-meshheading:20040594-Gram-Negative Facultatively Anaerobic Rods, pubmed-meshheading:20040594-Hydrogen-Ion Concentration, pubmed-meshheading:20040594-Kinetics, pubmed-meshheading:20040594-Molecular Sequence Data, pubmed-meshheading:20040594-Moritella, pubmed-meshheading:20040594-Oceans and Seas, pubmed-meshheading:20040594-Photobacterium, pubmed-meshheading:20040594-Protein Conformation, pubmed-meshheading:20040594-Recombinant Fusion Proteins, pubmed-meshheading:20040594-Seawater, pubmed-meshheading:20040594-Sequence Alignment, pubmed-meshheading:20040594-Sequence Analysis, DNA, pubmed-meshheading:20040594-Sequence Homology, Amino Acid, pubmed-meshheading:20040594-Shewanella, pubmed-meshheading:20040594-Temperature, pubmed-meshheading:20040594-Tetrahydrofolate Dehydrogenase
pubmed:year
2010
pubmed:articleTitle
Cloning and characterization of dihydrofolate reductases from deep-sea bacteria.
pubmed:affiliation
Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't