18F3

Site of transposon insertion cloned as PstI fragment into pSP72. 
Sequenced in opposite orientations with JEP131 and JEP132,
from sites at opposing ends of the transposon, to give:


JEP131 387 bp

JEP132 392 bp

Composite sequence:

ATATCACGCT CAGTTGATAT AACATCGTTC CTCCAGCGAA TAAGCACGCT
ACCGCCCTTG AGTTACAGCT CCCAATGCGC TATTAACAAA AACAAAATTG
ATCCTGCCAG GATATAAGTC AGCATGAATT AATCCTGAAA AATACAGATT
TATCCGCTTG TCGGCGGAAA TAAGTAAATA ACGTCAGCGT GCGGTTAAGT
TATCTATCAG AAAACTCATG TTTAATGGTT CTTTCGATTG CCGAATCAAG
TTCAACCGGC GCCACGAAAT TATTTTGCAC ATTACTTTTA AATTGCGTTC
TGGCGCAGAA TTTCTGCACT CTGACGCGAC TGATTGGGAA TTTTTTCGAC
TTATTTTACT CACGACATCC AAGCGGTCGC NGCGCAA

TTGANGCCCG CATATTCCCA CCACATAAGG AATGCGAATC GTCTTATTTT
CTCTGCCCAG CGAGGAGGAA ATAACGTCGA CCAATTGATT CATCCGTAAA
GTCCGGTTTA TCNGACGTAG TTGCTGACCT GATAACTTGA CTGCTGGTCC
AACGCATGCT CCAGCCGCGC GGCAATATTT TCAACGTAAG CCATCGACTT
CATATTATTG CCACTGCCAA TCATCACGAA TCGGCCGCTG GCGATCTGGC
GGAACAGGTT ATACACATTG CCGCGGTTGC CTTCACCGAA TACCACCGTC
GGGCGAATGA TGGTCAATTT GTTGGCGCTA TCCGCCTTGC GCCACGCTTC
ATAAACGTAT TCCGCTTCGA GCTTGGATTT GCCGTAATGA TC



BLASTX with this sequence (full results here) gives as most significant hit :


>gi|16648662|gb|AAL25633.1| (AY057452) UDP-glucose 4-epimerase [Edwardsiella ictaluri]
          Length = 323

 Score =  114 bits (286), Expect(3) = 2e-40
 Identities = 56/91 (61%), Positives = 66/91 (71%)
 Frame = -1

Query: 773 YGKSKLEAEYVYEAWRKADSANKLTIIRPTVVFGEGNRGNVYNLFRQIASGRFVMIGSGN 594
           YGKSKLEAE+ Y+AW+       L  +RPTVVFGE NRGNVYNLFRQIASG+F+MIG G 
Sbjct: 131 YGKSKLEAEFAYDAWQAKVPERTLVTVRPTVVFGENNRGNVYNLFRQIASGKFLMIGPGL 190

Query: 593 NMKSMAYVENIAARLEHALDQQSSYQVSNYV 501
           N KSMAYVEN+AA L  +    +   V NY+
Sbjct: 191 NQKSMAYVENMAAFLRFSTTMGAGRHVFNYI 221


 Score = 58.2 bits (139), Expect(3) = 2e-40
 Identities = 26/50 (52%), Positives = 37/50 (74%), Gaps = 2/50 (4%)
 Frame = -2

Query: 346 KKFPISRVRVQKFCARTQFKSN--VQNNFVAPVELDSAIERTIKHEFSDR 203
           ++FP+S +RV+KFCARTQFKSN   Q  F APV L+  I  T+++EF ++
Sbjct: 269 REFPVSSIRVKKFCARTQFKSNHIAQTGFKAPVTLEQGIANTVRYEFLEK 318


 Score = 33.9 bits (76), Expect(3) = 2e-40
 Identities = 17/44 (38%), Positives = 25/44 (56%)
 Frame = -3

Query: 480 MNQLVDVISSSLGRENKTIRIPYVVGICGXQLRXDRLDVVSKIS 349
           MN L  VI ++L R    IRIPY VG+ G        D+++K++
Sbjct: 228 MNDLTGVICTALHRHKNNIRIPYAVGLLGGYC----FDILAKVT 267

The transposon is thus inserted within a homologue of wbeiT, an UDP-glucose 4-epimerase.

This is said to be within the Edwardsiella ictaluri O antigen biosynthesis gene cluster.

O-antigens, have long been recognised as an important determinant of bacterial virulence in many bacteria (see for example this review by Rocchetta et al. on O-antigen biosynthesis in Pseudomonas aeruginosa).