PDBsum entry 1u6r

Transferase

PDB id: 1u6r

Contents

Protein chains

380 a.a. *

Ligands

ADP ×2

NO3

IOM

Metals

_MG ×2

Waters ×1155

* Residue conservation analysis

PDB id:

1u6r

Name:

Transferase

Title:

Transition state analog complex of muscle creatine kinase (r134k) mutant

Structure:

Creatine kinase, m chain. Chain: a, b. Synonym: m-ck. Engineered: yes. Mutation: yes

Source:

Oryctolagus cuniculus. Rabbit. Organism_taxid: 9986. Gene: ckm. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Dimer (from PQS)

Resolution:

1.65Å R-factor: 0.167 R-free: 0.200

Authors:

J.F.Ohren,M.L.Kundracik,C.L.Borders,P.Edmiston,R.E.Viola

Key ref:

J.F.Ohren et al. (2007). Structural asymmetry and intersubunit communication in muscle creatine kinase. Acta Crystallogr D Biol Crystallogr, 63, 381-389. PubMed id: 17327675

Date:

30-Jul-04 Release date: 02-Aug-05

Protein chains

P00563  (KCRM_RABIT) -  Creatine kinase M-type from Oryctolagus cuniculus

Seq: 381 a.a.

Struc: 380 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.7.3.2 - creatine kinase.
• Pathway: Creatine Biosynthesis
• Reaction: creatine + ATP = N-phosphocreatine + ADP + H⁺

creatine + ATP (Bound ligand (Het Group name = IOM) corresponds exactly) = N-phosphocreatine (Bound ligand (Het Group name = ADP) corresponds exactly) + ADP + H(+)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Acta Crystallogr D Biol Crystallogr 63:381-389 (2007)

PubMed id: 17327675

Structural asymmetry and intersubunit communication in muscle creatine kinase.

J.F.Ohren, M.L.Kundracik, C.L.Borders, P.Edmiston, R.E.Viola.

ABSTRACT

The structure of a transition-state analog complex of a highly soluble mutant (R134K) of rabbit muscle creatine kinase (rmCK) has been determined to 1.65 A resolution in order to elucidate the structural changes that are required to support and regulate catalysis. Significant structural asymmetry is seen within the functional homodimer of rmCK, with one monomer found in a closed conformation with the active site occupied by the transition-state analog components creatine, MgADP and nitrate. The other monomer has the two loops that control access to the active site in an open conformation and only MgADP is bound. The N-terminal region of each monomer makes a substantial contribution to the dimer interface; however, the conformation of this region is dramatically different in each subunit. Based on this structural evidence, two mutational modifications of rmCK were conducted in order to better understand the role of the amino-terminus in controlling creatine kinase activity. The deletion of the first 15 residues of rmCK and a single point mutant (P20G) both disrupt subunit cohesion, causing the dissociation of the functional homodimer into monomers with reduced catalytic activity. This study provides support for a structural role for the amino-terminus in subunit association and a mechanistic role in active-site communication and catalytic regulation.