Photosynthesis Research

, Volume 46, Issue 1–2, pp 93–105

Cryptomonad biliproteins — an evolutionary perspective

  • Alexander N. Glazer
  • Gary J. Wedemayer
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DOI: 10.1007/BF00020420

Cite this article as:
Glazer, A.N. & Wedemayer, G.J. Photosynth Res (1995) 46: 93. doi:10.1007/BF00020420

Abstract

Each cryptomonad strain contains only a single spectroscopic type of biliprotein. These biliproteins are isolated as ≈50000 kDa αα'β2 complexes which carry one bilin on the α and three on the β subunit. Six different bilins are present on the cryptomonad biliproteins, two of which (phycocyanobilin and phycoerythrobilin) also occur in cyanobacterial and rhodophytan biliproteins, while four are known only in the cryptomonads. The β subunit is encoded on the chloroplast genome, whereas the α subunits are encoded by a small nuclear multigene family. The β subunits of all cryptomonad biliproteins, regardless of spectroscopic type, have highly conserved amino acid sequences, which show > 80% identity with those of rhodophytan phycoerythrin β subunits. In contrast, cyanobacteria and red algal chloroplasts each contain several spectroscopically distinct biliproteins organized into macromolecular complexes (phycobilisomes). The data on biliproteins, as well as several other lines of evidence, indicate that the cryptomonad biliprotein antenna system is ‘primitive’ and antedates that of the cyanobacteria. It is proposed that the gene encoding the cryptomonad biliprotein β subunit is the ancestral gene of the gene family encoding cyanobacterial and rhodophytan biliprotein α and β subunits.

Key words

chloroplast evolution photosynthetic antennae serial endosymbiosis 

Abbreviations

Chl

chlorophyll

CER

chloroplast endoplasmic reticulum

SSU rRNA

small subunit ribosomal RNA

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Alexander N. Glazer
    • 1
  • Gary J. Wedemayer
    • 2
  1. 1.Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyUSA
  2. 2.Department of ChemistryUniversity of CaliforniaBerkeleyUSA

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