PMID- 17993521
OWN - NLM
STAT- MEDLINE
DCOM- 20080201
LR  - 20211020
IS  - 1098-5530 (Electronic)
IS  - 0021-9193 (Print)
IS  - 0021-9193 (Linking)
VI  - 190
IP  - 2
DP  - 2008 Jan
TI  - Three pathogenicity islands of Vibrio cholerae can excise from the chromosome and 
      form circular intermediates.
PG  - 636-47
AB  - Vibrio pathogenicity island-2 (VPI-2) is a 57-kb region integrated at a transfer 
      RNA (tRNA)-serine locus that encompasses VC1758 to VC1809 on the V. cholerae 
      N16961 genome and is present in pandemic isolates. VPI-2 encodes a P4-like 
      integrase, a restriction modification system, a Mu phage-like region, and a 
      sialic acid metabolism region, as well as neuraminidase (VC1784), which is a 
      glycosylhydrolase known to release sialic acid from sialoglycoconjugates to 
      unmask GM1 gangliosides, the receptor for cholera toxin. We examined the 
      tRNA-serine locus among the sequenced V. cholerae genomes and identified five 
      variant VPI-2 regions, four of which retained the sialometabolism region. Three 
      variant VPI-2 regions contained a type three secretion system. By using an 
      inverse nested PCR approach, we found that the VPI-2 region can form an 
      extrachromosomal circular intermediate (CI) molecule after precise excision from 
      its tRNA-serine attachment site. We constructed a knockout mutant of VC1758 (int) 
      with V. cholerae strain N16961 and found that no excision PCR product was 
      produced, indicating that a functional cognate, VPI-2 integrase, is required for 
      excision. The Vibrio seventh pandemic island-I (VSP-I) and VSP-II regions are 
      present in V. cholerae O1 El Tor and O139 serogroup isolates. Novel regions are 
      present at the VSP-I insertion site in strain MZO-3 and at the VSP-II insertion 
      site in strain 623-39. VSP-II is a 27-kb region that integrates at a 
      tRNA-methionine locus, is flanked by direct repeats, and encodes a P4-like 
      integrase. We show that VSP-II can excise and form a CI and that the cognate 
      VSP-II integrase is required for excision. Interestingly, VSP-I is not inserted 
      at a tRNA locus and does encode a XerDC-like recombinase, but similar to VPI-2 
      and VSP-II, VSP-I does excise from the genome to form a CI. These results show 
      that all three pathogenicity islands can excise from the chromosome, which is 
      likely a first step in their horizontal transfer.
FAU - Murphy, Ronan A
AU  - Murphy RA
AD  - Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
FAU - Boyd, E Fidelma
AU  - Boyd EF
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20071109
PL  - United States
TA  - J Bacteriol
JT  - Journal of bacteriology
JID - 2985120R
RN  - 0 (DNA, Bacterial)
RN  - 0 (DNA, Circular)
RN  - EC 2.7.7.- (Integrases)
SB  - IM
MH  - Chromosomes, Bacterial
MH  - DNA, Bacterial/*metabolism
MH  - DNA, Circular/*metabolism
MH  - Gene Deletion
MH  - *Genomic Islands
MH  - Integrases/genetics/physiology
MH  - Recombination, Genetic
MH  - Vibrio cholerae O1/*genetics
MH  - Vibrio cholerae O139/*genetics
MH  - Vibrio cholerae non-O1/*genetics
PMC - PMC2223681
EDAT- 2007/11/13 09:00
MHDA- 2008/02/02 09:00
PMCR- 2008/05/01
CRDT- 2007/11/13 09:00
PHST- 2007/11/13 09:00 [pubmed]
PHST- 2008/02/02 09:00 [medline]
PHST- 2007/11/13 09:00 [entrez]
PHST- 2008/05/01 00:00 [pmc-release]
AID - JB.00562-07 [pii]
AID - 0562-07 [pii]
AID - 10.1128/JB.00562-07 [doi]
PST - ppublish
SO  - J Bacteriol. 2008 Jan;190(2):636-47. doi: 10.1128/JB.00562-07. Epub 2007 Nov 9.