Biological Assembly 1  

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 38886.75 
• Atom Count: 2211 
• Residue Count: 333 
• Unique protein chains: 1

1KXU

CYCLIN H, A POSITIVE REGULATORY SUBUNIT OF CDK ACTIVATING KINASE

• DOI: 10.2210/pdb1KXU/pdb

• Classification: REGULATORY PROTEIN
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda


• Deposited: 1996-08-08 Released: 1997-01-27 
• Deposition Author(s): Kim, K.K., Chamberin, H.M., Morgan, D.O., Kim, S.-H.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.295 
• R-Value Work: 0.214 

Literature

Three-dimensional structure of human cyclin H, a positive regulator of the CDK-activating kinase.

Kim, K.K., Chamberlin, H.M., Morgan, D.O., Kim, S.H.

(1996) Nat.Struct.Mol.Biol. 3: 849-855

• PubMed: 8836101 


• PubMed Abstract: 
  

Cyclin-dependent kinases (CDKs), which play a key role in cell cycle control, are activated by the CDK activating kinase (CAK), which activates cyclin-bound CDKs by phosphorylation at a specific threonine residue. Vertebrate CAK contains two key components: a kinase subunit with homology to its substrate CDKs and a regulatory subunit with homology to cyclins. We have determined the X-ray crystal structure of the regulatory subunit of CAK, cyclin H, at 2.6 A resolution. Cyclin H contains two alpha-helical core domains with a fold similar to that of cyclin A, a regulatory subunit of CAK substrate CDK2, and of TFIIB, a transcription factor. Outside of the core domains, the N- and C-terminal regions of the three structures are completely different. The conformational differences between cyclin H and A structures may reflect functional differences between the two cyclins.

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Related Citations: 

• A Novel Cyclin Associates with Mo15/Cdk7 to Form the Cdk-Activating Kinase
  Fisher, R.P.,Morgan, D.O.
  (1994) Cell 78: 713




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Organizational Affiliation: 

Department of Chemistry, University of California, Berkeley 94720, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
CYCLIN H	A	333	Homo sapiens	Mutation(s): 0  Gene Names: CCNH
Find proteins for P51946 (Homo sapiens) Go to Gene View: CCNH Go to UniProtKB:  P51946

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.295 
• R-Value Work: 0.214 
• Space Group: I 4₁ 2 2

Unit Cell:

Length (Å)	Angle (°)
a = 84.080	α = 90.00
b = 84.080	β = 90.00
c = 374.880	γ = 90.00

Software Package:

Software Name	Purpose
X-PLOR	refinement
DENZO	data reduction
X-PLOR	phasing
SCALEPACK	data scaling
X-PLOR	model building

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1996-08-08 
• Released Date: 1997-01-27 
• Deposition Author(s): Kim, K.K., Chamberin, H.M., Morgan, D.O., Kim, S.-H.

Revision History 

• Version 1.0: 1997-01-27
  Type: Initial release
• Version 1.1: 2008-03-24
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance
• Version 1.3: 2011-11-16
  Type: Atomic model