Phosphatidylglycerophosphat-Synthasen aus Arabidopsis thaliana

Data base searches resulted in the identification of five A. thaliana genes encoding putative phosphatidyltransferases. Functional expression studies showed that the two genes AC01563 and AL35540 encode phosphatidylinositol synthases, while the gene AF118223.2 appeared to encode a cardiolipin synthase. The two remaining genes AC004697.2 and AL132970.2 were identified as phosphatidylglycerophosphate synthase (PGPS) genes. The deduced amino acid sequences are highly conserved at their C-terminal ends but differ in their N-terminal ends. Where, PGPS1 (AC004697.2) unlike PGPS2 (AL132970.2) was found to have a transit peptide. Both recombinant enzymes were solubilized with Triton X-100 and subsequently purified in their catalytically active form. The biochemical characterization of the purified proteins as well as the membrane bound forms revealed that the two PGPS isozymes display similar properties with regard to pH-optima, detergent stimulation and cation dependence. In addition, the two isozymes were found to have comparable KM values for both substrates but they differ in their CDP-diacylglycerol species specificities due to their different VMAX values. The analysis of an A. thaliana mutant carrying a T-DNA insertion in the PGPS1 gene revealed that this gene is responsible for 70 % of the total PGPS activity in wild type plants. Furthermore the results suggest that PGPS1 is imported into both Mitochondria and plastids. Moreover, it seems likely that phosphatidylglycerol can be imported into mitochondria from the endomembranes of A. thaliana.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2002

Author dc:creator

• Müller, Frank

Contributors dc:contributor

• Frentzen, Margarete

• info:eu-repo/classification/ddc/570
• Biowissenschaften, Biologie
• Ackerschmalwand
• CDP-Diacylglycerol-Glycerolphosphat-Phosphatidyltransferase
• Gen

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-118949%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A56872