Genome-wide identification and evolution of ATP-binding cassette transporters in the ciliate Tetrahymena thermophila: A case of functional divergence in a multigene family

Table 1 Comparison of ABC transporters in Tetrahymena thermophila and other eukaryotes

Family	Structure	Tt	Pt	Bb	Py	Dd	At	Sc	Hs
ABCA	(TMD-NBD)₂	29^a	20	0	0	7	0	0	13
	TMD-NBD	4	4	0	0	5	17^b	0	0
ABCB	(TMD-NBD)₂	13	7	0	1	2	22	1	4
	TMD-NBD	13	7	4	6	7	5	3	7
ABCC	(TMD-NBD)₂	60	46^c	4	1	14	15	7	12
ABCD	(TMD-NBD)₂	0	0	0	0	0	1	0	0
	TMD-NBD	2	4	0	0	3	1	2	4
ABCE	NBD-NBD	1	2	1	1	1	2	1	1
ABCF	NBD-NBD	2	2	1	1	4	5	5	3
ABCG	(TMD-NBD)₂	3	0	0	0	15	13	10	0
	TMD-NBD	36	17	0	1	6	29	1^d	5
Other^e	NBD	2	3	0	3	4	15	2	2
Total	-	165	112	10	14	68	125	32	50
Number of Genes	-	24725	39642	3671	5878	12500	25498	5538	22287
Percent	-	0.667%	0.283%	0.272%	0.238%	0.544%	0.490%	0.577%	0.224%

Tt = Tetrahymena thermophila, Pt = Paramecium tetraurelia, Bb = Babesia bovis (has the minimum predicted gene number in sequenced apicomplexans), Py = Plasmodium yoelii yoelii (has the maximum predicted gene number in sequenced apicomplexans), Dd = Dictyostelium discoideum, At = Arabidopsis thaliana, Sc = Saccharomyces cerevisiae, Hm = Homo sapiens
^a one incorrectly predicted gene was identified
^b includes a gene annotated as (TMD-NBD)₂ in a previous report, but revised as TMD-NBD in the current version of the annotation
^c includes 5 genes with a structure TMD-NBD and 2 genes with a structure NBD
^d this gene has three TMDs and one NBD
^e includes the ABCH family of gene

ISSN: 2730-7182