A peroxidase homologue and novel plastocyanin located by proteomics to the Arabidopsis chloroplast thylakoid lumen.
A study by two-dimensional electrophoresis showed that the soluble, lumenal fraction of Arabidopsis thaliana thylakoids can be resolved into 300 protein spots. After subtraction of low-intensity spots and accounting for low-level stromal contamination, the number of more abundant, lumenal proteins was estimated to be between 30 and 60. Two of these proteins have been identified: a novel plastocyanin that also was the predominant component of the total plastocyanin pool, and a putative ascorbate peroxidase. Import studies showed that these proteins are routed to the thylakoid lumen by the Sec- and delta pH-dependent translocation pathways, respectively. In addition, novel isoforms of PsbO and PsbQ were identified.
Kieselbach
T
T
Karolinska Institute, Department of Medical Nutrition, Huddinge, Sweden.
Bystedt
M
M
Hynds
P
P
Robinson
C
C
Schröder
W P
WP
D000595:Amino Acid Sequence; D017360:Arabidopsis; D060387:Ascorbate Peroxidases; D002458:Cell Fractionation; D002736:Chloroplasts; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000032:analysis* / Q000145:classification; D010970:Plastocyanin / Q000032:analysis* / Q000145:classification; D020543:Proteome / Q000032:analysis*; D017386:Sequence Homology, Amino Acid; D020524:Thylakoids / Q000737:chemistry*
D020543:Proteome; D010970:Plastocyanin; D010544:Peroxidases; D060387:Ascorbate Peroxidases