2Laboratory of Development Biology, Biological Science and Technology College, Shenyang Agricultural University, Shengyang 110161, China; E-mail: email@example.com
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Received April 17, 2008; Revision received June 2, 2008
In this study, we cloned the OsHAL3 gene from rice Oryza sativa. Alignment analysis revealed that OsHAL3 has a high sequence identity to Dfp protein in Escherichia coli and AtHAL3a protein in Arabidopsis thaliana, which have 4′-phosphopantothenoylcysteine decarboxylase (PPC-DC) activity. OsHAL3 can complement mutation in the E. coli dfp gene encoding PPC-DC, so that the mutant strains with OsHAL3 can grow on rich media at 42°C and on VB minimal media at 30°C. Complementation tests with point mutations of OsHAL3 suggested that the conserved Cys176 residue of OsHAL3 is a key active-site residue. The mutant OsHAL3 G180A has a partly reduced activity. Related mRNA-level analysis showed that the OsHAL3 gene is induced by calcium pantothenate in rice.
KEY WORDS: OsHAL3, 4′-phosphopantothenoylcysteine decarboxylase, coenzyme A, rice