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

Table 5 FNT channels with unique cytoplasmic slit in the closed state

FNT subfamily	UniProt ID^a (Organism)	Cytoplasmic slit residues^b	CHI/CVV value^c
YfdC-α	I9C2K5 (Novosphingobium sp.) J8 W598 (Sphingomonas sp.) K9CVI9 (Sphingobium yanoikuyae) L8XVV6 (Wohlfahrtiimonas chitiniclastica)	YLTM	CHI: +3.7
NirC-α	A3WW31 (Nitrobacter sp.) A4BNG3 (Nitrococcus mobilis) D5BVC1 (Nitrosococcus halophilus) I4EJX4 (Nitrolancea hollandica) Q82WJ4 (Nitrosomonas europaea)	YMTV	CHI: +4.1
YfdC-β	A5PEF7 (Erythrobacter sp.) M0BPP6 (Halovivax asiaticus)	VLSV	CVV: 407 Ǻ³

^aThe unique UniProt Accession ID is given
^bThe four residues that form cytoplasmic slit in the closed state of the channel. They correspond to L79 from TM2a, L89 and T91 from Ω-loop and V175 from TM4 of the formate channel (PDB ID: 3KCU). The residue shown in bold moves away from the cytoplasmic slit when the Ω-loop undergoes conformational changes so that FNT channel can make a transition from the closed to open state
^cCalculation of Cumulative Hydropathy Index (CHI) and Cumulative vdw Volume (CVV) are described in the text

ISSN: 1471-2164