Molecular cloning and phylogenetic analysis of a novel BURP domain-containing gene from Camellia sinensis

BURP domain-containing proteins are a new class of plant-specific proteins that play important roles in the growth, development and stress response of plants. In this paper, a novel BURP domain-containing gene from Camellia sinensis (CsBDP, GenBank accession No. EU715397) was isolated and cloned using reverse transcription-polymerase chain reaction (RT-PCR) followed by 5' and 3' rapid amplification of cDNA ends (RACE) reactions. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot were then applied to detect the expression of CsBDP gene in Escherichia coli. Sequence comparison showed that the deduced protein sequence of CsBDP gene shared high sequence similarity to other BURP domain-containing proteins and contained four typical modules: an N-terminal hydrophobic region, a short conserved segment, a variable region containing two repeats of about 19 amino acids, which is unique for the RD22-like proteins of BURP family and a C-terminal BURP domain. Furthermore, phylogenetic tree revealed that the BURP protein family can be classified into eight subfamilies, and CsBDP was distinctly clustered into subfamily III with all RD22-like proteins. Therefore, CsBDP gene might be a stress-inducible gene and important for the stress tolerance of tea plant.