Isolation, sequencing and characterization of cluster genes involved in the biosynthesis and utilization of the sideroph
- PDF / 485,726 Bytes
- 7 Pages / 595 x 791 pts Page_size
- 14 Downloads / 237 Views
S H O R T CO M MU N I C A T I O N
Isolation, sequencing and characterization of cluster genes involved in the biosynthesis and utilization of the siderophore of marine Wsh pathogen Vibrio alginolyticus Qiyao Wang · Qin Liu · Yue Ma · Lingyun Zhou · Yuanxing Zhang
Received: 15 January 2007 / Revised: 22 April 2007 / Accepted: 12 May 2007 / Published online: 26 June 2007 © Springer-Verlag 2007
Abstract In Wsh pathogen Vibrio alginolyticus MVP01, the isolated 11-gene cluster consisted of two divergently transcribed, Fe3+ and ferric uptake regulator (Fur) regulated operons, pvsABCDE and psuA-pvuABCDE, sharing high similarity with that related to siderophore biosynthesis and transportation locus in V. parahaemolyticus. Siderophore biosynthesis or utilization was blocked when pvsA and pvsD of the pvsABCDE operon or pvuA, pvuB and pvuE of the psuA-pvuABCDE operon was single-gene in-frame mutated, demonstrating their essential roles for siderophore biosynthesis or utilization in V. alginolyticus MVP01. Addition of the puriWed siderophore restored the cell growth in siderophore biosynthesis mutants, but not in siderophore uptake mutants. Keywords Vibrio alginolyticus · Siderophore · Biosynthesis · Uptake · Cluster gene · Plasposon
Introduction The ability to sequester bio-available dissolved ferric ions from environment is virtually essential for most bacteria for their optimal growth under iron-limiting milieu. In bacteria, siderophore mediated iron uptake mechanism is evolved for this purpose (Faraldo-Gomez and Sansom 2003). Siderophore biosynthesis and transportation genes are often clustered
Communicated by Erko Stackebrandt. Q. Wang · Q. Liu · Y. Ma · L. Zhou · Y. Zhang (&) State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, People’s Republic of China e-mail: [email protected]
present in chromosome or plasmid (Crosa and Walsh 2002). There exist two groups of enzymes, nonribosomal peptide synthetase (NRPS) (Crosa and Walsh 2002) and NRPS independent synthetase (NIS), being responsible for siderophore biosynthesis (Challis 2005). In gram-negative bacteria, ferric–siderophore complex is recognized by speciWc TonB-energized outer membrane receptors and then transferred to the sequential components such as periplasmic binding proteins and permease proteins (Faraldo-Gomez and Sansom 2003). In most cases, expression of the genes required for the biosynthesis and transportation of siderophore is readily under the co-regulation of bio-available iron concentration and ferric uptake regulation protein (Fur) to maintain the intracellular iron at a relative steady concentration for the optimal growth (Escolar et al. 1999). A moderately halophilic gram-negative bacterium, V. alginolyticus was initially considered to be a part of normal marine Xora (Verschuere et al. 2000) and now is suggested as an epizootic pathogen to several aquatic animals and to humans throughout Europe and Asia (Balebona et al. 1998; Gomez-Leon et al. 2005). In south China, V. alginolyticus
Data Loading...
