Structure and organization of two closely related low-temperature-induced dhn/lea/rab-like genes in Arabidopsis thaliana L. Heynh.
We have isolated a 7 kb EcoRI genomic fragment from Arabidopsis thaliana which contains, in a tandem arrangement, two closely related dhn/lea/rab-like genes, lti29 (formerly named lti45) and cor47, corresponding to previously isolated cDNA clones. Both transcripts have been shown to accumulate in response to low temperature (LT), abscisic acid (ABA) and dehydration. Alignment of the amino acid sequences of the deduced polypeptides showed that they are 67% identical. The calculated molecular masses of the two polypeptides were 29 kDa for LTI29 and 30 kDa for COR47. Both polypeptides contain one conserved serine-stretch and three lysine-rich repeats characteristic of DHN/LEA/RAB-like proteins. In addition, both LTI29 and COR47 harbour and N-terminal acidic repeat only found in a few members amongst the DHN/LEA/RAB proteins. The close distance between the two genes (separated by 2.7 kb) and their tandem organization in the A. thaliana genome as well as the overall homology at the nucleotide sequence level of the coding region suggest that the two genes have evolved through a duplication event. This seems to be a common feature among A. thaliana LT-responsive genes.
Welin
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Department of Molecular Genetics, Uppsala Genetic Center, Swedish University of Agricultural Sciences, Sweden.
Olson
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D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; C089006:ERD14 protein, Arabidopsis; C090419:LTI45 protein, Arabidopsis; D010940:Plant Proteins; C066246:late embryogenesis abundant protein, plant; C072393:COR47 protein, Arabidopsis