Viral photosynthetic reaction center genes and transcripts in the marine environment.
Cyanobacteria of the genera Synechococcus and Prochlorococcus are important contributors to photosynthetic productivity in the open ocean. The discovery of genes (psbA, psbD) that encode key photosystem II proteins (D1, D2) in the genomes of phages that infect these cyanobacteria suggests new paradigms for the regulation, function and evolution of photosynthesis in the vast pelagic ecosystem. Reports on the prevalence and expression of phage photosynthesis genes, and evolutionary data showing a potential recombination of phage and host genes, suggest a model in which phage photosynthesis genes help support photosynthetic activity in their hosts during the infection process. Here, using metagenomic data in natural ocean samples, we show that about 60% of the psbA genes in surface water along the global ocean sampling transect are of phage origin, and that the phage genes are undergoing an independent selection for distinct D1 proteins. Furthermore, we show that different viral psbA genes are expressed in the environment.
Sharon
Itai
I
Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
Tzahor
Shani
S
Williamson
Shannon
S
Shmoish
Michael
M
Man-Aharonovich
Dikla
D
Rusch
Douglas B
DB
Yooseph
Shibu
S
Zeidner
Gil
G
Golden
Susan S
SS
Mackey
Shannon R
SR
Adir
Noam
N
Weingart
Uri
U
Horn
David
D
Venter
J Craig
JC
Mandel-Gutfreund
Yael
Y
Béjà
Oded
O
D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D023281:Genomics; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex / Q000235:genetics; D048929:Prochlorococcus / Q000821:virology*; D012623:Seawater / Q000382:microbiology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D046940:Synechococcus / Q000821:virology*
D004279:DNA, Viral; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit