Cloning and Sequence Analysis of Actin Gene from Guzmania

As a house keeping gene, Actin was often used as inner control in quantitative and semiquantitative PCR tests to determine relative expressive amount of target genes. Based on EST monoclones of Actin gene obtained from Guzmania full length cDNA library, its full length cDNA sequence was obtained by Primer Walking sequencing. The gene, named for Goactin1 (GenBank accession No. HQ184438), consisted of 1 625 bp cDNA sequence, 1 131 bp ORF (open reading frame) which encoded a protein with 377 amino acids residues, and a putative protein which was 41.7 kD at estimated molecular weight, 5.31 at isoelectric point and had a ‘actin superfamily’conservative domain. The secondary structure of the protein was composed of random coil, alpha helix, extend strand and beta turn by SPOMA analysis. Furthermore, its tertiary structure was also build based on A chain of 2BTF. Through phylogenetic tree analysis, Goactin1 was gather to a same group with Actin protein in Solanum tuberosum , Gossypium hirsutum , Nicotiana tabacum , Brachypodium sylvaticum , and Arabidopsis thaliana .