Table 3. Characteristics of e-pilin genes found in non-Fe(III)-reducing bacterial species.

Organism	Type IVa pilin type	Immature pilin size (aa)	Mature pilin size (aa)	Leader sequence length	Accession number	#beta strands at C terminus*
Desulfobacterium autotrophicum	epilin	73	59	14	HRM2_27700	0
Hippea maritima	epilin	68	59	9	Hipma_0737	0
Hippea alviniae	epilin	70	61	9	G415DRAFT_0872	0
Deferribacter desulfuricans	epilin	67	59	8	DEFDS_1270	0
Flexistipes sinusarabici	epilin	74, 70	67, 60	7, 10	Flexsi_2291, Flexsi_2288	1, 0
Desulfobacula toluolica	epilin	71	58	13	TOL2_21350	0
Desulfobacula phenolica	epilin	72	59	13	Ga0066824_11648	1
Desulfobacula sp. TS	epilin	Partial sequence			Ga0097800_108051	0
Desulfobotulus alkaliphilus	epilin	73	60	13	LZ24DRAFT_00006	0
Desulfobotulus sapovorans	epilin	71	58	13	BR04DRAFT_00394	0
Thauera linaloolentis	epilin and long type 4a pilin	59, 150, 168	52, 144, 161	7, 6, 7	C666_06285, C666_05425, C666_15290	0, 4, 5
Thauera terpenica	epilin and long type 4a pilin	59, 137	52, 128	7, 9	M622_11345, M622_01585	0, 3
Thauera humireducens	epilin and long type 4a pilin	150, 60	144, 52	6, 8	WP_048709378, WP_048706629	4, 1

^*Beta strands were identified with the Jnet algorithm (Cuff & Barton, 2000) on the Jpred 4 server(Drozdetskiy, 2015).