Journal
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
Volume 78, Issue 7, Pages 2256-2263Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/AEM.07321-11
Keywords
-
Categories
Funding
- State Key Basic Research and Development Plan of China [2008CB418002]
- National Natural Science Foundation of China [31170189]
- National Water Science and Technology Projects [2009ZX07101-013-02]
- Chinese Academy of Sciences [082303-1-501]
Ask authors/readers for more resources
New insights into the distribution and biochemistry of the cyanotoxin cylindrospermopsin (CYN) have been provided by the recent determination of its biosynthesis gene cluster (cyr) in several cyanobacterial species. Raphidiopsis curvata CHAB1150 isolated from China was analyzed for CYN analogues. Only 7-deoxy-CYN was detected in the cell extracts. The cyr gene cluster of R. curvata CHAB1150 was sequenced, and the cyr genes of this strain were found to have extremely high similarities (96% to 100%) to those from other nostocalean species. These species include Cylindrospermopsis raciborskii AWT205, Aphanizomenon sp. strain 10E6, and Aphanizomenon ovalisporum ILC-146. Insertion mutation was identified within the cyrI gene, and transcripts of cyrI and another functional gene cyrJ were detected in R. curvata CHAB1150. General congruence between the phylogenetic trees based on both cyr and 16S rrn was displayed. Neutral evolution was found on the whole sequences of the cyr genes, and 0 to 89 negative selected codons were detected in each gene. Therefore, the function of CyrI is to catalyze the oxygenation of 7-deoxy-CYN in CYN biosynthesis. The transcripts of the mutated cyrI gene may result from polycistronic transcription. The high conservation of the cyr genes may be ascribed to purifying selection and horizontal gene transfer.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available