Pfl. Chang et al., Isolation and characterization of the third gene encoding a 16.9 kDa classI low-molecular-mass heat shock protein, Oshsp 16.9C, in rice, BOTAN B A S, 42(2), 2001, pp. 85-92
Using rice cDNA pTS1 encoding a 16.9 kDa heat shock protein (HSP) as a prob
e for Southern hybridization analysis, we observed five prominent bands of
9.5, 5.9, 3.4, 2.5, and 1.7 kb in the Eco RI digests of rice genomic DNA an
d found them to contain six individual genes. The 5.9 kb DNA fragment was f
urther digested with Hind m to generate three fragments of 3.5, 1.7 and 0.7
kb, and we found, using pTS1 cDNA as a probe, the 3.5 kb fragment containe
d a putative low-molecular-mass (LMM) HSP gene. The DNA sequencing of 3.5 k
b fragment revealed encoding of a presumptive 16.9 kDa HSP (149 amino acid
residues) with predicted pi value of 6.42. The nucleotide sequence of this
gene was highly homologous to the coding regions of two rice class I LMM HS
P genes, Oshsp, 16.9A and Oshsp16.9B, sharing 93.1% and 94.3% sequence iden
tity, respectively, as published previously in our laboratory. The deduced
amino acid sequence of this gene is similar to those of the Oshsp16.9A and
Oshsp16.9B genes with a difference of only ii and 10 amino acids, respectiv
ely. It was hence designated as Oshsp16.9C (accession no. U81385). We used
3' UTRs (untranslated regions) for analysis of Oshsp16.9C gene expression s
ince the 3' UTRs of these three genes showed Very low sequence homology.