1GS3

High resolution crystal structure of PI delta-5-3-Ketosteroid Isomerase mutants Y30F/Y55F/Y115F/D38N (Y32F/Y57F/Y119F/D40N, PI numbering)complexed with equilenin at 2.1 A resolution

Functional Information from GO Data

Chain	GOid	namespace	contents
A	0004769	molecular_function	steroid delta-isomerase activity
A	0008202	biological_process	steroid metabolic process
A	0016853	molecular_function	isomerase activity

Functional Information from PDB Data

site_id	AC1
Number of Residues	8
Details	BINDING SITE FOR RESIDUE EQU A 801

Chain	Residue
A	TYR16
A	ASN40
A	PHE86
A	MET90
A	ASN93
A	ASP103
A	MET116
A	TRP120

---

Functional Information from SwissProt/UniProt

site_id	SWS_FT_FI1
Number of Residues	1
Details	ACT_SITE: Proton donor

Chain	Residue	Details
A	TYR16

---

site_id	SWS_FT_FI2
Number of Residues	1
Details	ACT_SITE: Proton acceptor

Chain	Residue	Details
A	ASN40

---

site_id	SWS_FT_FI3
Number of Residues	1
Details	BINDING: BINDING => ECO:0000269|PubMed:11007792

Chain	Residue	Details
A	ASP103

---

Catalytic Information from CSA

site_id	CSA1
Number of Residues	5
Details	Annotated By Reference To The Literature 1e3v

Chain	Residue	Details
A	ASP103
A	ASN40
A	PHE32
A	TYR16
A	PHE57

---

site_id	MCSA1
Number of Residues	4
Details	M-CSA 349

Chain	Residue	Details
A	TYR16	proton acceptor, proton donor
A	ASN40	proton acceptor, proton donor
A	ASP100	electrostatic stabiliser
A	ASP103	electrostatic stabiliser

---