Genes encoding core components of the phycobilisome in the cyanobacterium Calothrix sp. strain PCC 7601: occurrence of a multigene family

Abstract

The phycobilisome is the major light-harvesting complex of cyanobacteria.

Multiple copies of a bile acid-inducible gene in Eubacterium sp. strain VPI 12708

“…The amino acid sequences for the 27K-1 and 27K-3 polypeptides are identical, whereas the 27K-1 and 27K-2 polypeptides show 92% sequence identity at the amino acid level. The baiA) and baiA3 genes share a block of homology that spans at least 2 kilobases of DNA, Although the exact function of the 27K polypeptides in 7-dehydroxylation of bile acids is not known, protein sequence surveys indicate that these polypeptides share strong homology with the nonzinc alcohol-polyol dehydrogenase class of enzymes, especially in the proposed pyridine nucleotide-binding domains (8,29,53 (11,25). Other examples include highly repetitive tRNA genes in Photobacterium phosphoreum (18), homologous acid-soluble spore proteins from Bacillus subtilis and Bacillus megaterium (9,16), duplicated tuf genes in numerous bacterial species (14,44), and homologous nif genes (40,49); there is also the possibility of numerous reiterated sequences in Rhizobium and Agrobacterium spp.…”

Characterization of a light-regulated gene encoding a new phycoerythrin-associated linker protein from the cyanobacterium Fremyella diplosiphon

“…The smallest protein band in the linker-protein region in both the R and G lanes corresponds to the constitutive rod-core linker. The band at -97 kDa is the anchor protein, which is believed to act as a terminal energy acceptor and to aid in attachment of the phycobilisome to the thylakoid membrane (13,19). The minor band at -50 kDa probably corresponds to the recently identified ferredoxin-NADP+ oxidoreductase which has been found associated in variable amounts with phycobilisomes due to a limited degree of similarity to linker proteins in its amino terminus (28).…”

“…of the rods, which contain, respectively, allophycocyanin and core linker proteins (18,19) and constitutive phycocyanin (cpcl) (7) with its associated rod-core linker protein. In red light, another phycocyanin operon (cpc2) encoding the inducible phycocyanin subunits and associated linker proteins is expressed, yielding phycobilisome rods composed exclusively of phycocyanin and associated linker proteins (6,7,21,23).…”

Tracking the Light Environment by Cyanobacteria and the Dynamic Nature of Light Harvesting

“…Often, polycistronic transcripts encode phycobiliprotein subunits and their associated L polypeptides. In F. diplosiphon, ␣ and ␤ AP subunits (␣ AP and ␤ AP , respectively), encoded by the apcA1B1 genes, are in an operon that also contains the apcC1 and apcE1 genes; the latter genes encode the core linker polypeptide and the L CM , respectively (8).…”