Chloroplast YidC homolog Albino3 can functionally complement the bacterial YidC depletion strain and promote membrane insertion of both bacterial and chloroplast thylakoid proteins.
A new component of the bacterial translocation machinery, YidC, has been identified that specializes in the integration of membrane proteins. YidC is homologous to the mitochondrial Oxa1p and the chloroplast Alb3, which functions in a novel pathway for the insertion of membrane proteins from the mitochondrial matrix and chloroplast stroma, respectively. We find that Alb3 can functionally complement the Escherichia coli YidC depletion strain and promote the membrane insertion of the M13 procoat and leader peptidase that were previously shown to depend on the bacterial YidC for membrane translocation. In addition, the chloroplast Alb3 that is expressed in bacteria is essential for the insertion of chloroplast cpSecE protein into the bacterial inner membrane. Surprisingly, Alb3 is not required for the insertion of cpSecE into the thylakoid membrane. These results underscore the importance of Oxa1p homologs for membrane protein insertion in bacteria and demonstrate that the requirement for Oxa1p homologs is different in the bacterial and thylakoid membrane systems.
Jiang
Fenglei
F
Department of Chemistry, Molecular Cellular Developmental Biology Program and Protein Research Group, The Ohio State University, Columbus, Ohio 43210, USA.
Yi
Liang
L
Moore
Misty
M
Chen
Minyong
M
Rohl
Thomas
T
Van Wijk
Klaas-Jan
KJ
De Gier
Jan-Willem L
JW
Henry
Ralph
R
Dalbey
Ross E
RE
D017360:Arabidopsis / Q000378:metabolism; D029681:Arabidopsis Proteins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D003576:Electron Transport Complex IV; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D005816:Genetic Complementation Test; D006863:Hydrogen-Ion Concentration; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins / Q000378:metabolism; D018532:Pisum sativum / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D020524:Thylakoids / Q000378:metabolism*
C106404:ALBINO 3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D018076:DNA, Complementary; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C090858:OXA1 protein; D010940:Plant Proteins; C412443:YIDC protein, E coli; D003576:Electron Transport Complex IV