1IS7

Crystal structure of rat GTPCHI/GFRP stimulatory complex

• PDB DOI: https://doi.org/10.2210/pdb1IS7/pdb

• Classification: HYDROLASE/PROTEIN BINDING
• Organism(s): Rattus norvegicus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2001-11-18 Released: 2002-02-20 
• Deposition Author(s): Maita, N., Okada, K., Hatakeyama, K., Hakoshima, T.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.264 
• R-Value Work: 0.228 

Literature

Crystal structure of the stimulatory complex of GTP cyclohydrolase I and its feedback regulatory protein GFRP.

Maita, N., Okada, K., Hatakeyama, K., Hakoshima, T.

(2002) Proc Natl Acad Sci U S A 99: 1212-1217

• PubMed: 11818540 
• DOI: https://doi.org/10.1073/pnas.022646999


• PubMed Abstract: 
  

  In the presence of phenylalanine, GTP cyclohydrolase I feedback regulatory protein (GFRP) forms a stimulatory 360-kDa complex with GTP cyclohydrolase I (GTPCHI), which is the rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin. The crystal structure of the stimulatory complex reveals that the GTPCHI decamer is sandwiched by two GFRP homopentamers. Each GFRP pentamer forms a symmetrical five-membered ring similar to beta-propeller. Five phenylalanine molecules are buried inside each interface between GFRP and GTPCHI, thus enhancing the binding of these proteins. The complex structure suggests that phenylalanine-induced GTPCHI x GFRP complex formation enhances GTPCHI activity by locking the enzyme in the active state.

---

Organizational Affiliation: 

Department of Molecular Biology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.

Biological Assembly 1  

Global Symmetry: Dihedral - D5  (Explore in 3D)
Global Stoichiometry: Hetero 20-mer - A10B10 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 357.07 kDa 
• Atom Count: 22,375 
• Modelled Residue Count: 2,780 
• Deposited Residue Count: 3,140 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
GTP Cyclohydrolase I	A, B, C, D, E, F, G, H, I, J	230	Rattus norvegicus	Mutation(s): 0  EC: 3.5.4.16
UniProt
Find proteins for P22288 (Rattus norvegicus) Explore P22288  Go to UniProtKB:  P22288

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
GTP Cyclohydrolase I Feedback Regulatory Protein	K, L, M, N, O, P, Q, R, S, T	84	Rattus norvegicus	Mutation(s): 0
UniProt
Find proteins for P70552 (Rattus norvegicus) Explore P70552  Go to UniProtKB:  P70552

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PHE	BA [auth N], DA [auth O], FA [auth P], IA [auth R], JA [auth R], LA [auth S], NA [auth T], V [auth K], X [auth L], Z [auth M]	PHENYLALANINE C9 H11 N O2 COLNVLDHVKWLRT-QMMMGPOBSA-N
K	AA [auth N], CA [auth O], EA [auth P], GA [auth Q], HA [auth R], KA [auth S], MA [auth T], U [auth K], W [auth L], Y [auth M]	POTASSIUM ION K NPYPAHLBTDXSSS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.264 
• R-Value Work: 0.228 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 124.151	α = 90
b = 111.723	β = 97.37
c = 126.108	γ = 90

Software Package:

Software Name	Purpose
MLPHARE	phasing
CNS	refinement
MOSFLM	data reduction
CCP4	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2002-02-20 
Deposition Author(s): Maita, N., Okada, K., Hatakeyama, K., Hakoshima, T.

Revision History  

• Version 1.0: 2002-02-20
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2023-12-27
  Changes: Data collection, Database references, Derived calculations