Linked Life Data

7849015

Source:http://linkedlifedata.com/resource/pubmed/id/7849015

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-3-13
pubmed:abstractText
To ascertain the minimal structural requirements for formation of the subunit and core light-harvesting complex (LH1), the alpha- and beta-polypeptides of the LH1 from three purple photosynthetic bacteria were enzymatically or chemically truncated or modified. These polypeptides were then used in reconstitution experiments with bacteriochlorophyll a (BChla), and the formation of subunit and LH1 complexes was evaluated using absorbance and circular dichroism spectroscopies. Truncation or modification outside of the conserved core sequence region of the polypeptides had no effect on subunit or LH1 formation. However, the extent of formation and stability of the subunit and LH1 decreased as the polypeptide was shortened inside the core region within the N-terminal domain. This behavior was suggested to be due to the loss of potential ion-pairing and/or hydrogen-bonding interactions between the polypeptides. While the spectroscopic properties of the subunit complexes generated using truncated polypeptides were analogous to those obtained using native polypeptides, in some cases the resulting LH1 complex absorption was blue-shifted relative to the control. Thus, truncation within the N-terminal domain may have long-range effects on the immediate BChla binding environment, since the putative BChla binding site resides near the C-terminal end of the polypeptides. It was also demonstrated that the His located within the membrane-spanning domain on the N-terminal end of the beta-polypeptide is not participating in ligation of the BChla in the reconstituted subunit and therefore probably not in LH1.
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
7
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1559-74
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Enzymatic and chemical cleavage of the core light-harvesting polypeptides of photosynthetic bacteria: determination of the minimal polypeptide size and structure required for subunit and light-harvesting complex formation.
pubmed:affiliation
Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.