title: Sec-independent protein translocation by the maize Hcf106 protein.
abstract: The bacterial Sec and signal recognition particle (ffh-dependent) protein translocation mechanisms are conserved between prokaryotes and higher plant chloroplasts. A third translocation mechanism in chloroplasts [the proton concentration difference (DeltapH) pathway] was previously thought to be unique. The hcf106 mutation of maize disrupts the localization of proteins transported through this DeltapH pathway in isolated chloroplasts. The Hcf106 gene encodes a receptor-like thylakoid membrane protein, which shows homology to open reading frames from all completely sequenced bacterial genomes, which suggests that the DeltapH pathway has been conserved since the endosymbiotic origin of chloroplasts. Thus, the third protein translocation pathway, of which HCF106 is a component, is found in both bacteria and plants.
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Settles
authors.forename: A
authors.initials: A
authors.lastname: Yonetani
authors.forename: A
authors.initials: A
authors.lastname: Baron
authors.forename: D R
authors.initials: DR
authors.lastname: Bush
authors.forename: K
authors.initials: K
authors.lastname: Cline
authors.forename: R
authors.initials: R
authors.lastname: Martienssen
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D002352:Carrier Proteins / Q000378:metabolism; D060365:Chloroplast Proteins; D002736:Chloroplasts / Q000737:chemistry / Q000378:metabolism*; D019143:Evolution, Molecular; D017343:Genes, Plant; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008744:Methylamines / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D010940:Plant Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D060365:Chloroplast Proteins; C109236:Hcf106 protein, plant; D008565:Membrane Proteins; D008744:Methylamines; D010940:Plant Proteins; C027451:methylamine