Functional analysis of the Arabidopsis thaliana GCPE protein involved in plastid isoprenoid biosynthesis.
Plastid isoprenoids are synthesized via the 2-C-methyl-D-erythritol 4-phosphate pathway. A few years after its discovery, most of the Escherichia coli genes involved in the pathway have been identified, including gcpE. In this work, we have identified an Arabidopsis thaliana protein with homology to the product of this gene. The plant polypeptide, GCPE, contains two structural domains that are absent in the E. coli protein: an N-terminal extension and a central domain of 30 kDa. We demonstrate that the N-terminal region targets the Arabidopsis protein to chloroplasts in vivo, consistent with its role in plastid isoprenoid biosynthesis. Although the presence of the internal extra domain may have an effect on activity, the Arabidopsis mature GCPE was able to complement a gcpE-defective E. coli strain, indicating the plant protein is a true functional homologue of the bacterial gcpE gene product.
Querol
Jordi
J
Departament de Bioquímica i Biologia Molecular, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-7, 08028 Barcelona, Spain.
Campos
Narciso
N
Imperial
Santiago
S
Boronat
Albert
A
Rodríguez-Concepción
Manuel
M
D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D010088:Oxidoreductases; D018087:Plastids / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013729:Terpenes / Q000378:metabolism*
D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; D013729:Terpenes; D010088:Oxidoreductases; C000708271:AT5G60600 protein, Arabidopsis