Split Photosystem Protein, Linear-Mapping Topology, and Growth of Structural Complexity in the Plastid Genome of Chromera velia

0422243 - MBÚ 2014 RIV US eng J - Journal Article
Janouškovec, J. - Sobotka, Roman - Lai, De Hua - Flegontov, Pavel - Koník, P. - Komenda, Josef - Ali, S. - Prášil, Ondřej - Pain, A. - Oborník, Miroslav - Lukeš, Julius - Keeling, P. J.
Split Photosystem Protein, Linear-Mapping Topology, and Growth of Structural Complexity in the Plastid Genome of Chromera velia.
Molecular Biology and Evolution. Roč. 30, č. 11 (2013), s. 2447-2462. ISSN 0737-4038. E-ISSN 1537-1719
R&D Projects: GA ČR GAP506/12/1522; GA ČR GBP501/12/G055; GA MŠMT(CZ) ED2.1.00/03.0110
Institutional support: RVO:61388971 ; RVO:60077344
Keywords : plastid genome evolution * Chromera velia * split protein
Subject RIV: CE - Biochemistry
Impact factor: 14.308, year: 2013

The canonical photosynthetic plastid genomes consist of a single circular-mapping chromosome that encodes a highly conserved protein core, involved in photosynthesis and ATP generation. Here, we demonstrate that the plastid genome of the photosynthetic relative of apicomplexans, Chromera velia, departs from this view in several unique ways. Core photosynthesis proteins PsaA and AtpB have been broken into two fragments, which we show are independently transcribed, oligoU-tailed, translated, and assembled into functional photosystem I and ATP synthase complexes. Genome-wide transcription profiles support expression of many other highly modified proteins, including several that contain extensions amounting to hundreds of amino acids in length. Canonical gene clusters and operons have been fragmented and reshuffled into novel putative transcriptional units. Massive genomic coverage by paired-end reads, coupled with pulsed-field gel electrophoresis and polymerase chain reaction, consistently indicate that the C. velia plastid genome is linear-mapping, a unique state among all plastids. Abundant intragenomic duplication probably mediated by recombination can explain protein splits, extensions, and genome linearization and is perhaps the key driving force behind the many features that defy the conventional ways of plastid genome architecture and function
Permanent Link: http://hdl.handle.net/11104/0228449