TABLE 1.

Summary of genes in E. coli O121 O-antigen gene cluster

ORFa	Proposed gene name	Locationb	No. of amino acids	Putative function	Most significant homolog (accession no.)c	% Identity/% similarityd
1	wbqA	153-1433	426	UDP-glucose-6-dehydrogenase	WbgT from Shigella sonnei (AAG17418)	71/84
2	wbqB	1449-2498	349	UDP-glucose-4-epimerase	WbgU from Shigella sonnei (AAG17419)	70/82
3	rmlB	2501-3589	362	dTDP-glucose-4,6-dehydratase	RmlB from Salmonella enterica (AAG09513)	71/81
4	rmlA	3556-4455	299	Glucose-1-phosphate thymidylyltransferase	RmlA from Aeromonas hydrophila (AAM22545)	72/85
5	vioA	4455-5558	367	dTDP-4-amino-4,6-dideoxyglucose aminotransferase	VioA from Pseudomonas aeruginosa (AAK15326)	58/75
6	wbqC	5555-6271	208	Unknown function	Hypothetical protein from Bordetella (CAA07645)	35/51
7	wbqD	6261-6683	140	Acetyltransferase	Acetyltransferase from Thermoanaerobacter tengcongensis (AAM23813)	37/53
8	wzx	6793-8187	464	O-antigen flippase	Wzx from E. coli O55:H7 (AAL67558)	21/42
9	wbqE	8193-9083	296	Glycosyltransferase	Glycosyltransferase from Clostridium acetobutylicum (AAK80301)	35/59
10	wbqF	9086-9607	173	Acetyltransferase	Acetyltransferase from Thermotoga maritima (AAD35754)	39/59
11	wzy	9639-10829	396	O-antigen polymerase	Wzy from E. coli O7:K1 (AAD44158)	20/47
12	wbqG	10837-12729	630	Asparagine synthase	WbpS from Pseudomonas aeruginosa (AAF24002)	55/70
13	wbqH	12684-13841	385	Glycosyltransferase	WbpT from Pseudomonas aeruginosa (AAF23993)	46/68
14	wbqI	13842-14966	374	Glycosyltransferase	WbpU from Pseudomonas aeruginosa (AAF23992)	53/70

^aORF, open reading frame.

^bLocation of the open reading frame in nucleotides.

^cSequences can be accessed via Entrez at the NCBI website (http://www.ncbi.nih.gov/).

^dPercent identity and percent similarity of the open reading frame to the most significant homolog.