PDBsum entry: 1qb0

Hydrolase

PDB id: 1qb0

Contents

Protein chain

178 a.a. *

Ligands

SO4 ×2

BME ×2

Metals

_CL

Waters ×379

* Residue conservation analysis

PDB id:

1qb0

Name:

Hydrolase

Title:

Human cdc25b catalytic domain

Structure:

Protein (m-phase inducer phosphatase 2 (cdc25b)). Chain: a. Fragment: catalytic domain. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Cellular_location: cytoplasm. Gene: cdc25b. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.91Å R-factor: 0.143

Authors:

K.D.Watenpaugh,R.A.Reynolds

Key ref:

R.A.Reynolds et al. (1999). Crystal structure of the catalytic subunit of Cdc25B required for G2/M phase transition of the cell cycle. J Mol Biol, 293, 559-568. PubMed id: 10543950 DOI: 10.1006/jmbi.1999.3168

Date:

29-Apr-99 Release date: 29-Apr-00

Protein chain

P30305  (MPIP2_HUMAN) -  M-phase inducer phosphatase 2

Seq: 580 a.a.

Struc: 178 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.3.48 - Protein-tyrosine-phosphatase.
• Reaction: Protein tyrosine phosphate + H₂O = protein tyrosine + phosphate

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

 Gene Ontology (GO) functional annotation 

• Cellular component: intracellular (1 term)
• Biological process: M phase of mitotic cell cycle (2 terms)
• Biochemical function: protein tyrosine phosphatase activity (1 term)

reference

DOI no: 10.1006/jmbi.1999.3168

J Mol Biol 293:559-568 (1999)

PubMed id: 10543950

Crystal structure of the catalytic subunit of Cdc25B required for G2/M phase transition of the cell cycle.

R.A.Reynolds, A.W.Yem, C.L.Wolfe, M.R.Deibel, C.G.Chidester, K.D.Watenpaugh.

ABSTRACT

Cdc25B is a dual specificity phosphatase involved in the control of cyclin-dependent kinases and the progression of cells through the cell cycle. A series of minimal domain Cdc25B constructs maintaining catalytic activity have been expressed. The structure of a minimum domain construct binding sulfate was determined at 1.9 A resolution and a temperature of 100 K. Other forms of the same co?nstruct were determined at lower resolution and room temperature. The overall folding and structure of the domain is similar to that found for Cdc25A. An important difference between the two is that the Cdc25B domain binds oxyanions in the catalytic site while that of Cdc25A appears unable to bind oxyanions. There are also important conformational differences in the C-terminal region. In Cdc25B, both sulfate and tungstate anions are shown to bind in the catalytic site containing the signature motif (HCxxxxxR) in a conformation similar to that of other protein tyrosine phosphatases and dual specificity phosphatases, with the exception of the Cdc25A. The Cdc25B constructs, with various truncations of the C-terminal residues, are shown to have potent catalytic activity. When cut back to the site at which the Cdc25A structure begins to deviate from the Cdc25B structure, the activity is considerably less. There is a pocket extending from the catalytic site to an anion-binding site containing a chloride about 14 A away. The catalytic cysteine residue, Cys473, can be oxidized to form a disulfide linkage to Cys426. A readily modifiable cysteine residue, Cys484, resides in another pocket that binds a sulfate but not in the signature motif conformation. This region of the structure is highly conserved between the Cdc25 molecules and could serve some unknown function.

Selected figure(s)

Figure 1.
Figure 1. Alignment of catalytic domains of Cdc25B (construct III) and Cdc25A used in the crystal structure determinations. Disor- dered and secondary domains are indicated above and below the sequences. Residues encircling the catalytic site are underlined.

Figure 2.
Figure 2. Superposition of Cdc25B (green) and Cdc25A (yellow, PDB accession code 1c25) catalytic domains. Groups from Cdc25B structure included with atoms color coded: carbon, green; oxygen, red; sulfur, yellow; and chlorine, white.

The above figures are reprinted by permission from Elsevier: J Mol Biol (1999, 293, 559-568) copyright 1999.

Figures were selected by an automated process.