Table 1.

Conservation of Acidic Residues in Class I Bacterial Receptors^a

position	no. of acidic residues	no. of acidic and Gln residues	% acidic	% acidic and Gln
270	5	7	38.5	53.8
273	9	10	69.2	76.9
281	12	13	92.3	100.0
288	11	12	84.6	92.3
294	11	11	84.6	84.6
295	2	10	15.4	76.9
301	12	12	92.3	92.3
302	9	13	69.2	100.0
308	12	12	92.3	92.3
309	1	11	7.7	84.6
319	9	9	69.2	69.2
452	8	8	61.5	61.5
456	11	11	84.6	84.6
462	9	9	69.2	69.2
463	11	12	84.6	92.3
469	7	7	53.8	53.8
477	7	10	53.8	76.9
479	10	10	76.9	76.9
491	11	12	84.6	92.3
500	7	7	53.8	53.8
501	7	7	53.8	53.8

^aAdaptation sites are underlined. Conservation of charge is reported for 13 class I bacterial receptors (20).