2NPK

An unusual twin-His arrangement in the pore of ammonia channels is essential for substrate conductance

Functional Information from GO Data

Chain	GOid	namespace	contents
A	0005515	molecular_function	protein binding
A	0005886	cellular_component	plasma membrane
A	0008519	molecular_function	ammonium transmembrane transporter activity
A	0015670	biological_process	carbon dioxide transport
A	0016020	cellular_component	membrane
A	0042802	molecular_function	identical protein binding
A	0072488	biological_process	ammonium transmembrane transport

Functional Information from PDB Data

site_id	AC1
Number of Residues	3
Details	BINDING SITE FOR RESIDUE SO4 A 501

Chain	Residue
A	ARG124
A	PHE125
A	SER126

---

site_id	AC2
Number of Residues	5
Details	BINDING SITE FOR RESIDUE ACT A 601

Chain	Residue
A	ALA158
A	ASP160
A	TYR278
A	GOL801
A	HOH950

---

site_id	AC3
Number of Residues	5
Details	BINDING SITE FOR RESIDUE SO4 A 901

Chain	Residue
A	LYS39
A	ASN40
A	ARG122
A	LYS184
A	ARG37

---

site_id	AC4
Number of Residues	6
Details	BINDING SITE FOR RESIDUE IMD A 701

Chain	Residue
A	GLN104
A	PHE107
A	TRP148
A	PHE161
A	SER219
A	HOH986

---

site_id	AC5
Number of Residues	6
Details	BINDING SITE FOR RESIDUE GOL A 801

Chain	Residue
A	PHE161
A	SER219
A	ALA220
A	TYR278
A	ACT601
A	HOH950

---

Functional Information from PROSITE/UniProt

site_id	PS01219
Number of Residues	26
Details	AMMONIUM_TRANSP Ammonium transporters signature. DFAGGtvVainAAiaGLvgaYLiGkR

Chain	Residue	Details
A	ASP160-ARG185

---

Functional Information from SwissProt/UniProt

site_id	SWS_FT_FI1
Number of Residues	71
Details	TOPO_DOM: Periplasmic => ECO:0000269|PubMed:15361618, ECO:0000269|PubMed:15563598, ECO:0000269|PubMed:17040913

Chain	Residue	Details
A	ALA1-ASN10
A	GLY69-GLN97
A	GLY150-GLY163
A	ALA220-ILE226
A	ILE279-GLY280
A	ALA334-MET348

---

site_id	SWS_FT_FI2
Number of Residues	236
Details	TRANSMEM: Helical => ECO:0000269|PubMed:15361618, ECO:0000269|PubMed:15563598, ECO:0000269|PubMed:17040913

Chain	Residue	Details
A	ALA11-TYR32
A	CYS312-ALA333
A	GLY349-ALA377
A	MET44-PHE68
A	TYR98-ALA120
A	PHE125-GLY149
A	GLY164-ALA179
A	MET200-SER219
A	ALA227-ALA251
A	LEU258-TYR278
A	VAL281-VAL299

---

site_id	SWS_FT_FI3
Number of Residues	48
Details	TOPO_DOM: Cytoplasmic => ECO:0000269|PubMed:15361618, ECO:0000269|PubMed:15563598, ECO:0000269|PubMed:17040913

Chain	Residue	Details
A	GLY33-SER43
A	GLU121-ARG124
A	TYR180-PRO199
A	LEU252-SER257
A	THR300-PRO311

---

site_id	SWS_FT_FI4
Number of Residues	28
Details	TOPO_DOM: Cytoplasmic => ECO:0000269|PubMed:15361618, ECO:0000269|PubMed:15563598, ECO:0000269|PubMed:15919996, ECO:0000269|PubMed:17040913

Chain	Residue	Details
A	ASP378-ALA406

---

site_id	SWS_FT_FI5
Number of Residues	1
Details	BINDING: BINDING => ECO:0000269|PubMed:15361618

Chain	Residue	Details
A	SER219

---

site_id	SWS_FT_FI6
Number of Residues	1
Details	SITE: Important for the deprotonation of the ammonium cation => ECO:0000269|PubMed:19278252

Chain	Residue	Details
A	ASP160

---

site_id	SWS_FT_FI7
Number of Residues	2
Details	SITE: Twin-His motif. Important for optimum substrate conductance => ECO:0000305|PubMed:17040913, ECO:0000305|PubMed:23667517, ECO:0000305|PubMed:32662768

Chain	Residue	Details
A	ALA168
A	ALA318

---

site_id	SWS_FT_FI8
Number of Residues	1
Details	SITE: Important for optimum substrate conductance => ECO:0000305|PubMed:18362341

Chain	Residue	Details
A	PHE215

---