PDBsum entry 1u2h

Contractile protein

PDB id: 1u2h

Contents

Protein chain

96 a.a. *

Waters ×150

* Residue conservation analysis

PDB id:

1u2h

Name:

Contractile protein

Title:

X-ray structure of the n-terminally truncated human apep-1

Structure:

Aortic preferentially expressed protein 1. Chain: a. Fragment: residues 15-113. Synonym: apeg-1. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: arotic preferentially expressed gene 1. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: psf clone id 111408 and rzpd id psfep250b117

Resolution:

0.96Å R-factor: 0.161 R-free: 0.172

Authors:

B.A.Manjasetty,C.Scheich,Y.Roske,F.H.Niesen,F.Gotz,K.Bussow, U.Heinemann

Key ref:

B.A.Manjasetty et al. (2005). X-ray structure of engineered human Aortic Preferentially Expressed Protein-1 (APEG-1). Bmc Struct Biol, 5, 21. PubMed id: 16354304

Date:

19-Jul-04 Release date: 05-Jul-05

Protein chain

Q15772  (SPEG_HUMAN) -  Striated muscle preferentially expressed protein kinase from Homo sapiens

Seq: 3267 a.a.

Struc: 96 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.2.7.11.1 - non-specific serine/threonine protein kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺

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

reference

Bmc Struct Biol 5:21 (2005)

PubMed id: 16354304

X-ray structure of engineered human Aortic Preferentially Expressed Protein-1 (APEG-1).

B.A.Manjasetty, F.H.Niesen, C.Scheich, Y.Roske, F.Goetz, J.Behlke, V.Sievert, U.Heinemann, K.Büssow.

ABSTRACT

BACKGROUND: Human Aortic Preferentially Expressed Protein-1 (APEG-1) is a novel specific smooth muscle differentiation marker thought to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). RESULTS: Good quality crystals that were suitable for X-ray crystallographic studies were obtained following the truncation of the 14 N-terminal amino acids of APEG-1, a region predicted to be disordered. The truncated protein (termed DeltaAPEG-1) consists of a single immunoglobulin (Ig) like domain which includes an Arg-Gly-Asp (RGD) adhesion recognition motif. The RGD motif is crucial for the interaction of extracellular proteins and plays a role in cell adhesion. The X-ray structure of DeltaAPEG-1 was determined and was refined to sub-atomic resolution (0.96 A). This is the best resolution for an immunoglobulin domain structure so far. The structure adopts a Greek-key beta-sandwich fold and belongs to the I (intermediate) set of the immunoglobulin superfamily. The residues lying between the beta-sheets form a hydrophobic core. The RGD motif folds into a 310 helix that is involved in the formation of a homodimer in the crystal which is mainly stabilized by salt bridges. Analytical ultracentrifugation studies revealed a moderate dissociation constant of 20 microM at physiological ionic strength, suggesting that APEG-1 dimerisation is only transient in the cell. The binding constant is strongly dependent on ionic strength. CONCLUSION: Our data suggests that the RGD motif might play a role not only in the adhesion of extracellular proteins but also in intracellular protein-protein interactions. However, it remains to be established whether the rather weak dimerisation of APEG-1 involving this motif is physiologically relevant.