General Information

The entry DI1010105 describes the same interaction with the disordered partner bearing different post-translational modification(s).

Database Accession: DI1010103

Name: cAMP-dependent protein kinase catalytic subunit in complex with cAMP-dependent protein kinase inhibitor

PDB ID: 1cmk PDB

Experimental method: X-ray (2.90 Å)

Source organism: Homo sapiens / Sus scrofa

Proof of disorder: Inferred from homology

Primary publication of the structure:

Zheng J, Knighton DR, Xuong NH, Taylor SS, Sowadski JM, Ten Eyck LF
Crystal structures of the myristylated catalytic subunit of cAMP-dependent protein kinase reveal open and closed conformations.

(1993) Protein Sci. 2: 1559-73

PMID: 8251932 PubMed


Three crystal structures, representing two distinct conformational states, of the mammalian catalytic subunit of cAMP-dependent protein kinase were solved using molecular replacement methods starting from the refined structure of the recombinant catalytic subunit ternary complex (Zheng, J., et al., 1993a, Biochemistry 32, 2154-2161). These structures correspond to the free apoenzyme, a binary complex with an iodinated inhibitor peptide, and a ternary complex with both ATP and the unmodified inhibitor peptide. The apoenzyme and the binary complex crystallized in an open conformation, whereas the ternary complex crystallized in a closed conformation similar to the ternary complex of the recombinant enzyme. The model of the binary complex, refined at 2.9 A resolution, shows the conformational changes associated with the open conformation. These can be described by a rotation of the small lobe and a displacement of the C-terminal 30 residues. This rotation of the small lobe alters the cleft interface in the active-site region surrounding the glycine-rich loop and Thr 197, a critical phosphorylation site. In addition to the conformational changes, the myristylation site, absent in the recombinant enzyme, was clearly defined in the binary complex. The myristic acid binds in a deep hydrophobic pocket formed by four segments of the protein that are widely dispersed in the linear sequence. The N-terminal 40 residues that lie outside the conserved catalytic core are anchored by the N-terminal myristylate plus an amphipathic helix that spans both lobes and is capped by Trp 30. Both posttranslational modifications, phosphorylation and myristylation, contribute directly to the stable structure of this enzyme.

Function and Biology Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown.

Molecular function: not assigned

Biological process:

regulation of cell cycle process Any process that modulates a cellular process that is involved in the progression of biochemical and morphological phases and events that occur in a cell during successive cell replication or nuclear replication events. GeneOntology

Cellular component:

nucleus A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent. GeneOntology

cytoplasm All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. GeneOntology

Structure Summary Structural annotations of the participating protein chains.

Entry contents: 2 distinct polypeptide molecules

Chains: I, E

Notes: No modifications of the original PDB file.

Chain I

Name: cAMP-dependent protein kinase inhibitor alpha Disordered Inferred from homology

Source organism: Homo sapiens

Length: 22 residues


UniProtKB AC: P61925 (positions: 6-27) UniProt Coverage: 28.9%

UniRef90 AC: UniRef90_P61925 (positions: 6-27) UniRef90

Chain E

Name: cAMP-dependent protein kinase catalytic subunit alpha Ordered

Source organism: Sus scrofa

Length: 350 residues


UniProtKB AC: P36887 (positions: 2-351) UniProt Coverage: 99.7%

UniRef90 AC: UniRef90_P17612 (positions: 2-351) UniRef90

Evidence Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding.

Chain I: Disordered Inferred from homology

The 1-76 region described in DisProt entry DP00015 and the 1-32 region describen in IDEAL entry IID00349 cover 100% of the binding sequence in a homologous protein.

Chain E: Ordered

The protein kinase domain involved in the interaction is known to adopt a stable structure in isolation (see Pfam domain PF00069). A solved monomeric structure of the domain is represented by PDB ID 1i09.

Related Structure(s) Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap).

There are 93 related structures in the Protein Data Bank:

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