f The marine cyanobacterium Synechococcus sp. WH7805 requires urease (urea amiohydrolase, EC 220.127.116.11) to utilize urea as a nitrogen source: molecular-genetic and biochemical analysis of the enzyme
- Authors: Jackie L. Collier†, Bianca Brahamsha, Brian Palenik
- Author for correspondence: Jackie L. Collie. Tel: +1 518 276 2178. Fax: +1 518 276 2162. e-mail: email@example.com
- First Published Online: 01 February 1999, Microbiology 145: 447-459, doi: 10.1099/13500872-145-2-447
- Subject: Genetics And Molecular Biology
- Issue Published:
Summary: Cyanobacteria assigned to the genus Synechococcus are an important component of oligotrophic marine ecosystems, where their growth may be constrained by low availability of fixed nitrogen. Urea appears to be a major nitrogen resource in the sea, but little molecular information exists about its utilization by marine organisms, including Synechococcus. Oligonucleotide primers were used to amplify a conserved fragment of the urease (urea amidohydrolase, EC 18.104.22.168) coding region from cyanobacteria. A 5·7 kbp region of the genome of the unicellular marine cyanobacterium Synechococcus sp. strain WH7805 was then cloned, and genes encoding three urease structural subunits and four urease accessory proteins were sequenced and identified by homology. The WH7805 urease had a predicted subunit composition typical of bacterial ureases, but the organization of the WH7805 urease genes was unique. Biochemical characteristics of the WH7805 urease enzyme were consistent with the predictions of the sequence data. Physiological data and sequence analysis both suggested that the urease operon may be nitrogen-regulated by the ntcA system in WH7805. Inactivation of the large subunit of urease, ureC, prevented WH7805 and Synechococcus WH8102 from growing on urea, demonstrating that the urease genes cloned are essential to the ability of these cyanobacteria to utilize urea as a nitrogen source.
Present address: Biology Department, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
The GenBank accession numbers for the sequences reported in this paper are AF065139 and AF056189.
© Society For General Microbiology 1999 | Published by the Microbiology Society
Article metrics loading...
Full text loading...
Author and Article Information
/content/journal/micro/10.1099/13500872-145-2-447dcterms_title,dcterms_subject,pub_serialTitlepub_serialIdent:journal/micro AND -contentType:BlogPost104
/content/journal/micro/10.1099/13500872-145-2-447dcterms_title,dcterms_subject-pub_serialIdent:journal/micro AND -contentType:BlogPost104
Figure data loading....