TABLE 3.

Size variation for twenty phylogenetic clusters of MscS family homologues^a

Cluster no.	Organismal type	No. of proteins	Average sized ± SD	Average no. of TMS ± SD by:
				WHATb	TOPPRED2c
I	Gram-negative bacteria	9	710 ± 57	8.9 ± 3.0	9.0 ± 2.8
II	High-G+C gram-positive bacteria	4	370 ± 57	4.0 ± 1.2	4.0 ± 1.2
III	Low-G+C gram-positive bacteria	6	270 ± 18	3.0 ± 0	3.0 ± 0.5
IV	Archaea	7	290 ± 8.0	4.6 ± 0.8	4.3 ± 1.0
V	Gram-negative bacteria	5	290 ± 14	3.6 ± 0.6	3.6 ± 0.6
VI	Gram-negative bacteria	11	290 ± 16	3.4 ± 1.3	3.5 ± 0.5
VII	Gram-negative bacteria	7	1,100 ± 6.0	11 ± 0.5	12 ± 0.7
VIII	Gram-negative bacteria	6	440 ± 62	5.2 ± 2.8	4.7 ± 2.4
IX	Archaea	2	290 ± 18	3.0 ± 0	3.0 ± 0
X	Archaea and spiroplasma	7	300 ± 33	4.0 ± 1.2	3.6 ± 1.0
XI	Plants	2	580 ± 140	4.0 ± 1.4	3.0 ± 1.4
XII	Archaea	2	360 ± 8.0	5.0 ± 0	4.0 ± 0
XIII	Gram-negative bacteria and low-G+C gram-positive bacteria	4	370 ± 16	5.0 ± 0	5.3 ± 0.5
XIV	Gram-negative bacteria	2	630 ± 3.0	4.0 ± 0	5.5 ± 0.7
XV	Archaea	3	290 ± 33	4.3 ± 0.6	4.0 ± 1.0
XVI	Gram-negative bacteria	2	520 ± 0	5.0 ± 1.4	3.0 ± 0
XVII	Eukaryotes	8	870 ± 89	6.1 ± 1.1	6.4 ± 0.7
XVIII	Gram-negative bacteria	5	420 ± 20	3.9 ± 1.1	4.6 ± 0.9
XIX	Gram-negative bacteria	6	270 ± 44	3.8 ± 1.0	3.2 ± 1.5
XX	Mixed	3	360 ± 34	3.3 ± 2.5	4.0 ± 1.0

^aProteins described in Table 2 footnote a are thought to be incompletely sequenced fragments and therefore were not included in this study.

^bAverage number of TMSs within that cluster predicted using the WHAT program (59).

^cAverage number of TMSs within that cluster predicted using the TOPPRED2 program (47).

^dNumber of amino acids.