Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-3-23
pubmed:abstractText
The major light-harvesting chlorophyll a/b-binding protein (Lhcb1,2) of photosystem II is inserted into the thylakoid via the signal recognition particle dependent pathway. However, the mechanism by which the protein enters the membrane is at this time unknown. In order to define some topographical restrictions for this process, we constructed several recombinant derivatives of Lhcb1 carrying hexahistidine tags at either protein terminus or in the stromal loop domain. Additionally, green fluorescent protein (GFP) was fused to either terminus. None of the modifications significantly impair the pigment-binding properties of the protein in the in vitro reconstitution of LHCII. With the exception of the C-terminal GFP fusion, all mutants stably insert into isolated thylakoids in the absence of Ni2+ ions. The addition of low concentrations of Ni2+ ions abolishes the thylakoid insertion of C-terminally His-tagged mutants whereas the other His-tagged proteins fail to insert only at higher Ni2+ concentrations. The C-terminus of Lhcb1 must cross the membrane during protein insertion whereas the other sites of Lhcb1 modification are positioned on the stromal side of LHCII. We conclude that a Ni2+-complexed His tag and fusion to GFP inhibit translocation of the protein C-terminus across the thylakoid. Our observations indicate that the N-terminal and stromal domain of Lhcb1 need not traverse the thylakoid during protein insertion and are consistent with a loop mechanism in which only the C-terminus and the lumenal loop of Lhcb1 are translocated across the thylakoid.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Green Fluorescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Histidine, http://linkedlifedata.com/resource/pubmed/chemical/Light-Harvesting Protein Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Luminescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nickel, http://linkedlifedata.com/resource/pubmed/chemical/Photosynthetic Reaction Center..., http://linkedlifedata.com/resource/pubmed/chemical/Photosystem II Protein Complex, http://linkedlifedata.com/resource/pubmed/chemical/Pigments, Biological, http://linkedlifedata.com/resource/pubmed/chemical/Plant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1138-45
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed-meshheading:10672023-Biological Transport, pubmed-meshheading:10672023-Carrier Proteins, pubmed-meshheading:10672023-Green Fluorescent Proteins, pubmed-meshheading:10672023-Histidine, pubmed-meshheading:10672023-Intracellular Membranes, pubmed-meshheading:10672023-Light, pubmed-meshheading:10672023-Light-Harvesting Protein Complexes, pubmed-meshheading:10672023-Luminescent Proteins, pubmed-meshheading:10672023-Molecular Weight, pubmed-meshheading:10672023-Mutation, pubmed-meshheading:10672023-Nickel, pubmed-meshheading:10672023-Peas, pubmed-meshheading:10672023-Photosynthetic Reaction Center Complex Proteins, pubmed-meshheading:10672023-Photosystem II Protein Complex, pubmed-meshheading:10672023-Pigments, Biological, pubmed-meshheading:10672023-Plant Proteins, pubmed-meshheading:10672023-Recombinant Fusion Proteins, pubmed-meshheading:10672023-Thylakoids
pubmed:year
2000
pubmed:articleTitle
Insertion of light-harvesting chlorophyll a/b protein into the thylakoid topographical studies.
pubmed:affiliation
Institut für Allgemeine Botanik, Johannes Gutenberg-Universität Mainz, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't