Format

Send to

Choose Destination
See comment in PubMed Commons below
Phytochemistry. 2013 Oct;94:68-73. doi: 10.1016/j.phytochem.2013.05.017. Epub 2013 Jun 28.

Identification of the thiamin salvage enzyme thiazole kinase in Arabidopsis and maize.

Author information

1
Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA.

Abstract

The breakdown of thiamin (vitamin B1) and its phosphates releases a thiazole moiety, 4-methyl-5-(2-hydroxyethyl)thiazole (THZ), that microorganisms and plants are able to salvage for re-use in thiamin synthesis. The salvage process starts with the ATP-dependent phosphorylation of THZ, which in bacteria is mediated by ThiM. The Arabidopsis and maize genomes encode homologs of ThiM (At3g24030 and GRMZM2G094558, respectively). Plasmid-driven expression of either plant homolog restored the ability of THZ to rescue Escherichia coli thiM deletant strains, showing that the plant proteins have ThiM activity in vivo. Enzymatic assays with purified recombinant proteins confirmed the presence of THZ kinase activity. Furthermore, ablating the Arabidopsis At3g24030 gene in a thiazole synthesis mutant severely impaired rescue by THZ. Collectively, these results show that ThiM homologs are the main source of THZ kinase activity in plants and are consequently crucial for thiamin salvage.

KEYWORDS:

Arabidopsis thaliana; Brassicaceae; Comparative genomics; Poaceae; Salvage; Thiamin; Thiazole; Zea mays

PMID:
23816351
DOI:
10.1016/j.phytochem.2013.05.017
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center