Identification of two genes encoding the major light-harvesting chlorophyll a/b proteins of photosystem II in green alga Dunaliella salina

摘要

Dunaliella salina is a useful model for studying the respective roles of each LHCII protein at the molecular level in extreme environmental conditions. However, information about the LhcII genes in D. salina is very limited. In order to identify more LhcII genes in D. salina, two additional LhcII cDNAs were obtained by screening a cDNA library. The genomic DNA was amplified by PCR using a specific primer set corresponding to the 5 ' and 3 ' untranslated regions of each transcript. The untranslated regions of the two additional genes are obviously different from each other; therefore they are two genes. Each gene contains an open reading frame for a protein of 253 amino acids. The two deduced proteins in D. salina are 99% identical at the amino acid sequence level to the previously reported LHCII protein in the same genus D. tertiolecta. Unrooted phylogenetic tree showed that types of LHCII proteins in D. salina did not correspond to any types in C. reinhardtii.