Linked Life Data

20173737

Source:http://linkedlifedata.com/resource/pubmed/id/20173737

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7285
pubmed:dateCreated
2010-3-5
pubmed:databankReference
pubmed:abstractText
Nitrogen (N(2))-fixing marine cyanobacteria are an important source of fixed inorganic nitrogen that supports oceanic primary productivity and carbon dioxide removal from the atmosphere. A globally distributed, periodically abundant N(2)-fixing marine cyanobacterium, UCYN-A, was recently found to lack the oxygen-producing photosystem II complex of the photosynthetic apparatus, indicating a novel metabolism, but remains uncultivated. Here we show, from metabolic reconstructions inferred from the assembly of the complete UCYN-A genome using massively parallel pyrosequencing of paired-end reads, that UCYN-A has a photofermentative metabolism and is dependent on other organisms for essential compounds. We found that UCYN-A lacks a number of major metabolic pathways including the tricarboxylic acid cycle, but retains sufficient electron transport capacity to generate energy and reducing power from light. Unexpectedly, UCYN-A has a reduced genome (1.44 megabases) that is structurally similar to many chloroplasts and some bacteria, in that it contains inverted repeats of ribosomal RNA operons. The lack of biosynthetic pathways for several amino acids and purines suggests that this organism depends on other organisms, either in close association or in symbiosis, for critical nutrients. However, size fractionation experiments using natural populations have so far not provided evidence of a symbiotic association with another microorganism. The UCYN-A cyanobacterium is a paradox in evolution and adaptation to the marine environment, and is an example of the tight metabolic coupling between microorganisms in oligotrophic oceanic microbial communities.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1476-4687
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
464
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
90-4
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Metabolic streamlining in an open-ocean nitrogen-fixing cyanobacterium.
pubmed:affiliation
Ocean Sciences Department, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't