A genomic clone of a type I cab gene encoding a light harvesting chlorophyll a/b binding protein of photosystem II identified from lodgepole pine

Abstract

A type I cab gene encoding chlorophyll a and b binding protein from lodgepole pine (Pinus contorta Dougl., var. latifolia (Engelm.)) has been isolated and sequenced. The gene encodes a proposed 40 amino acid transit peptide and a 234 amino acid mature CAB polypeptide. There is no evidence of an intron and examination of the type-specific amino acids confirm this to be a photosystem II type I cab gene. The coding region is highly conserved with a similar gene from Scots pine, the homology extending into the 5′ and 3′ untranslated regions. Sequence comparison of the 1-kb region upstream of the translation start codon from the lodgepole pine cab gene exhibited little similarity to identified regulatory regions in pea, tobacco, wheat, and Arabidopsis cab genes. The cab gene, which is 62% G + C rich, is surrounded by 70–75% A + T rich regions, which may confer some regulatory feature on its expression.Key words: chlorophyll a/b binding protein, gymnosperm, lodgepole pine, photosystem II type I cab gene.