Linked Life Data

14967022

Source:http://linkedlifedata.com/resource/pubmed/id/14967022

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2004-2-17
pubmed:abstractText
A gene for photoactive yellow protein (PYP) was previously cloned from Rhodobacter capsulatus (Rc), and we have now found it to be associated with genes for gas vesicle formation in the recently completed genome sequence. However, the PYP had not been characterized as a protein. We have now produced the recombinant RcPYP in Escherichia coli as a glutathione-S-transferase (GST) fusion protein, along with the biosynthetic enzymes, resulting in the formation of holo-RcPYP following cleavage of the GST tag. The absorption spectrum (with characteristic peaks at 435 and 375 nm) and the photocycle kinetics, initiated by a laser flash at 445 nm, are generally similar to those of Rhodobacter sphaeroides (RsPYP) but are significantly different from those of the prototypic PYP from Halorhodospira halophila (HhPYP), which has a single peak at 446 nm and has slower recovery. RcPYP also is photoactive when excited with near-ultraviolet laser light, but the end point is then above the preflash baseline. This suggests that some of the PYP chromophore is present in the cis-protonated conformation in the resting state. The excess 435 nm form in RcPYP, built up from repetitive 365 nm laser flashes, returns to the preflash baseline with an estimated half-life of 2 h, which is markedly slower than that for the same reaction in RsPYP. Met100 has been reported to facilitate cis-trans isomerization in HhPYP, yet both Rc and RsPYPs have Lys and Gly substitutions at positions 99 and 100 (using HhPYP numbering throughout) and have 100-fold faster recovery kinetics than does HhPYP. However, the G100M and K99Q mutations of RcPYP have virtually no effect on kinetics. Apparently, the RcPYP M100 is in a different conformation, as was recently found for the PYP domain of Rhodocista centenaria Ppr. The cumulative results show that the two Rhodobacter PYPs are clearly distinct from the other species of PYP that have been characterized. These properties also suggest a different functional role, that we postulate to be in regulation of gas vesicle genes, which are known to be light-regulated in other species.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1809-20
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:14967022-Bacterial Proteins, pubmed-meshheading:14967022-Gene Expression Regulation, Bacterial, pubmed-meshheading:14967022-Genome, Bacterial, pubmed-meshheading:14967022-Glutamine, pubmed-meshheading:14967022-Glycine, pubmed-meshheading:14967022-Hydrogen-Ion Concentration, pubmed-meshheading:14967022-Kinetics, pubmed-meshheading:14967022-Lysine, pubmed-meshheading:14967022-Methionine, pubmed-meshheading:14967022-Multigene Family, pubmed-meshheading:14967022-Mutagenesis, Site-Directed, pubmed-meshheading:14967022-Photolysis, pubmed-meshheading:14967022-Photoreceptors, Microbial, pubmed-meshheading:14967022-Rhodobacter capsulatus, pubmed-meshheading:14967022-Spectrometry, Mass, Matrix-Assisted Laser..., pubmed-meshheading:14967022-Spectrophotometry, Ultraviolet, pubmed-meshheading:14967022-Temperature
pubmed:year
2004
pubmed:articleTitle
Rhodobacter capsulatus photoactive yellow protein: genetic context, spectral and kinetics characterization, and mutagenesis.
pubmed:affiliation
Laboratory of Protein Biochemistry and Protein Engineering, University of Gent, Ledeganckstraat 35, 9000 Gent, Belgium. jkyndt@email.arizona.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't