cyanobacterium UCYN-A

Names cyanobacterium UCYN-A
Accession numbers NC_013771
Background Cyanobacteria are (usually) oxygenic, phototrophic organisms. They normally encode two photosystems (PSI and PSII) releasing electrons from water and fix carbon dioxide via the Calvin-Benson-Bassham pathway. Thus they absorb large quantities of C(O)2 and produce (O)2. Some cyanobacteria are also able to fix (N)2.UCYN-A is a globally distributed, periodically abundant (N)2-fixing marine cyanobacterium. It was recently found to lack the oxygen producing PSII complex of the photosynthetic apparatus, indicating a novel metabolism. DNA was sequenced from UCYN-A cells sorted using flow cytometry from sea water at 15 m depth collected at Station ALOHA in the North Pacific subtropical gyre 100 km north of Hawaii and assembled to give the complete genome. At 1.44 Mb the genome is unusually small for a cyanobacterium and lacks a number of major metabolic pathways including the tricarboxylic acid cycle, the Calvin cycle, biosynthesis of several amino acids and de novo purine biosynthesis but retains sufficient electron transport capacity to generate energy and reducing power from light. It is closely related to Cyanothece ATCC 51142, CYAA5. The metabolic potential defined by the genome indicates that UCYN-A is either an obligate endosymbiont of a cryptic symbiotic partner or that it is adapted to obtain organic nutrition from the low concentration of organic matter in the ocean, perhaps during the demise of phytoplankton blooms (adapted from PMID 20173737). (HAMAP: UCYNA)
Strain UCYN-A
Complete Yes
Sequencing centre (18-DEC-2009) Ocean Sciences, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
(29-JAN-2010) National Center for Biotechnology Information, NIH, Bethesda, MD 20894, USA
Sequencing quality NA
Sequencing depth NA
Sequencing method NA
Isolation site NA
Isolation country NA
Number of replicons 1
Gram staining properties NA
Shape NA
Mobility No
Flagellar presence No
Number of membranes 2
Oxygen requirements NA
Optimal temperature NA
Temperature range NA
Habitat Aquatic
Biotic relationship NA
Host name NA
Cell arrangement NA
Sporulation NA
Metabolism NA
Energy source NA
Diseases NA
Pathogenicity No