Anion-selective Formate/nitrite transporters: taxonomic distribution, phylogenetic analysis and subfamily-specific conservation pattern in prokaryotes

Table 6 FNT channels with unique cytoplasmic slit in the open state

FNT subfamily	UniProt ID^a (Organism)	Cytoplasmic slit residues^b	CHI/CVV value^c
NirC-α	A3WW31(Nitrobacter sp.) A4BNG3 (Nitrococcus mobilis) D5BVC1 (Nitrosococcus halophilus) I4EJX4 (Nitrolancea hollandica) Q82WJ4 (Nitrosomonas europaea)	YMANV	CHI: +3.1
HSC	F0JF84 (Desulfovibrio desulfuricans)	LLVTL	CHI: +14.9
NirC-γ	S4D5T6, V7ZKG7 (Enterococcus faecalis) S4EBH9, T2NT11 (Enterococcus faecium) T0U7W5 (Enterococcus sp.) T4JYM3 (Peptoclostridium difficile) U5SBH7 (Carnobacterium inhibens) V5XL10 (Enterococcus mundtii) and 41 more	LLGNV	CVV: 497 Ǻ³
Unclassified	I0JHL8 (Halobacillus halophilus) K2GJH2 (Salimicrobium jeotgali) L5N8D2 (Halobacillus sp.) Q8ES73 (Oceanobacillus iheyensis)	YLFNI	CVV: 620 Ǻ³

^aThe unique UniProt Accession ID is given
^bThe five residues that form cytoplasmic slit in the open state of the channel. They correspond to L79 from TM2a, L89 and F90 from Ω-loop and N172 and V175 from TM4 of the formate channel (PDB ID: 3KCU). Residues shown in bold will become part of the cytoplasmic slit in the open state when the Ω-loop undergoes conformational changes
^cCalculation of Cumulative Hydropathy Index (CHI) and Cumulative vdw Volume (CVV) are described in the text

ISSN: 1471-2164