Comparison of the O antigens of Shigella boydii types 10 and 6 by chemical analysis and nuclear magnetic resonance spectroscopy showed that their structures are similar, with the only difference being the presence or absence of d-ribofuranose, which is the immunodominant sugar in S. boydii type 10. In S. boydii type 6, a residue previously reported as α-D-GlcpA, was shown to be β-D-GlcpA as in S. boydii type 10. S. boydii types 10 and 6 are reported not to cross-react serologically, and the role of d-ribofuranose in the specificity of S. boydii was confirmed by making a mutant of type 10 that lacked d-ribofuranose. However, S. boydii type 11, which has a d-ribofuranose but with different linkage does show cross-reaction with type 10. The O-antigen gene loci of S. boydii types 10 and 6 were shown to be virtually identical except that orf8 (wbaM), which was confirmed as the ribofuranosyltransferase gene, is interrupted by IS629 in type 6. Therefore, it is proposed that the O-antigen gene cluster of S. boydii type 6 was derived from type 10 by an IS element insertion.

genetic, synthesis, antigen, structure, gene, PCR, structural, characterization, O-antigen, O antigen, Escherichia, Escherichia coli, type, function, heteropolysaccharide, assay, transporter, development

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6	C7	C8	C9
3,3,5	Ac	174.7-175.2	23.7
3,3	aXNeup	177.6	97.8	40.6	77.5	51.7	71.9	69.8	71.9	64.6
3,2	Am	167.7	20.5
3	aLFucpN	97.3	54.3	69.1	72.3	68.4	16.8
2	Ac	174.7-175.2	23.7
	bDGlcpN	103.0	57.0	79.7	69.8	77.1	62.0


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9
3,3,5	Ac	-	1.98-2.06
3,3	aXNeup	-	-	1.89-2.41	4.10	3.99	3.99	3.52	3.77	3.61-3.82
3,2	Am	?	2.30
3	aLFucpN	5.17	3.87	4.04	3.85	4.45	1.19
2	Ac	-	1.98-2.06
	bDGlcpN	4.56	3.85	3.72	3.50	3.48	3.76-3.94


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6	C7/H7	C8/H8	C9/H9
3,3,5	Ac		23.7/1.98-2.06
3,3	aXNeup			40.6/1.89-2.41	77.5/4.10	51.7/3.99	71.9/3.99	69.8/3.52	71.9/3.77	64.6/3.61-3.82
3,2	Am	167.7/?	20.5/2.30
3	aLFucpN	97.3/5.17	54.3/3.87	69.1/4.04	72.3/3.85	68.4/4.45	16.8/1.19
2	Ac		23.7/1.98-2.06
	bDGlcpN	103.0/4.56	57.0/3.85	79.7/3.72	69.8/3.50	77.1/3.48	62.0/3.76-3.94

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1C[C@](O[C@H]2[C@H](NC(C)=N)[C@H](O[C@@H]3[C@@H](NC(C)=O)[C@H](*)O[C@H](CO)[C@H]3O)O[C@@H](C)[C@H]2O)(C(=O)O)O[C@@H]([C@H](O)[C@H](O)CO)[C@@H]1NC(C)=O

680.661 g/mol (C₂₇H₄₄R₂N₄O₁₆, R = next and previous repeats, not counted in mol weight)