Molecular and General Genetics MGG

, Volume 263, Issue 1, pp 152–158

Minicircular plastid DNA in the dinoflagellate Amphidinium operculatum

  • A. C. Barbrook
  • C. J. Howe

DOI: 10.1007/s004380050042

Cite this article as:
Barbrook, A. & Howe, C. Mol Gen Genet (2000) 263: 152. doi:10.1007/s004380050042


Plastid DNA was purified from the dinoflagellate Amphidinium operculatum. The genes atpB, petD, psaA, psbA and psbB have been shown to reside on single-gene minicircles of a uniform size of 2.3–2.4 kb. The psaA and psbB genes lack conventional initiation codons in the expected positions, and may use GTA for translation initiation. There are marked biases in codon preference. The predicted PsbA protein lacks the C-terminal extension which is present in all other photosynthetic organisms except Euglena gracilis, and there are other anomalies elsewhere in the predicted amino acid sequences. The non-coding regions of the minicircles contain a “core” region which includes a number of stretches that are highly conserved across all minicircles and modular regions that are conserved within subsets of the minicircles.

Key words MinicircleDinoflagellatePlastid DNACodon biasEndosymbiosis

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • A. C. Barbrook
    • 1
  • C. J. Howe
    • 1
  1. 1.Department of Biochemistry and Cambridge Centre for Molecular Recognition, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK E-mail:; Fax: +44-1223-333345GB