Research Article
Manoj Nath, Anshita Goel, G
Abstract
Calmodulin gene (CaM) - a calcium sensor was cloned by the technique of polymerase chain reaction (PCR) from cereals and millets using single set of primer designed from Eleusine coracana ESTs available in dbEST database. The PCR amplicons of 613bp were consistently observed in all cereals and millets except Setaria italica. The amplicons from these cereals were further gel eluted, cloned, sequenced and subjected to homology search, multiple sequence alignment, phylogenetic tree construction and motif analysis. The homology search con fi rmed their identity to CaM genes except for Triticum aestivum. Multiple sequence alignment of the translated CaM amino acid sequences con fi rmed the presence of conserved consensus sequences of 110 amino acids, which was uniformly observed across different cereals and millets except Sorghum bicolor. Phylogenetic tree constructed based on protein sequences of cloned CaM genes revealed closed evolutionary relationship between three varieties of Eleusine coracana (PRM-1, PRM-701 and PRM-801) and Hordeum vulgare as compared to other cereals and millets which also possess higher concentration of calcium in seeds. Thus indicates that structural variation in CaM has some role in the differential accumulation of calcium. Three EF-hands associated with a CaM gene were present consistently except Sorghum bicolor, having only two EF-hands. The in silico 3D-structural analysis of cloned sequences showed similar pattern and reveals high degree of conservation in CaM in terms of structure and interaction with calcium ions, thus re fl ecting to further investigate the role of CaM isoforms, their expression patterns and downstream interaction with transport machinery involved in calcium accumulation.