4E1Q

Crystal structure of Wheat Cyclophilin A at 1.25 A resolution

Summary for 4E1Q

• Entry DOI: 10.2210/pdb4e1q/pdb
• Descriptor: Peptidyl-prolyl cis-trans isomerase (2 entities in total)
• Functional Keywords: isomerase
• Biological source: Triticum aestivum (wheat)
• Total number of polymer chains: 1
• Total formula weight: 22245.34

Authors

Sekhon, S.S.,Jeong, D.G.,Woo, E.J.,Singh, P.,Yoon, T.S. (deposition date: 2012-03-06, release date: 2013-03-27, Last modification date: 2024-03-20)

Primary citation

Sekhon, S.S.,Kaur, H.,Dutta, T.,Singh, K.,Kumari, S.,Kang, S.,Park, S.G.,Park, B.C.,Jeong, D.G.,Pareek, A.,Woo, E.J.,Singh, P.,Yoon, T.S.
Structural and biochemical characterization of the cytosolic wheat cyclophilin TaCypA-1
Acta Crystallogr.,Sect.D, 69:555-563, 2013

PubMed Abstract: Cyclophilins belong to a family of proteins that bind to the immunosuppressive drug cyclosporin A (CsA). Several members of this protein family catalyze the cis-trans isomerization of peptide bonds preceding prolyl residues. The present study describes the biochemical and structural characteristics of a cytosolic cyclophilin (TaCypA-1) cloned from wheat (Triticum aestivum L.). Purified TaCypA-1 expressed in Escherichia coli showed peptidyl-prolyl cis-trans isomerase activity, which was inhibited by CsA with an inhibition constant of 78.3 nM. The specific activity and catalytic efficiency (kcat/Km) of the purified TaCypA-1 were 99.06 ± 0.13 nmol s(-1) mg(-1) and 2.32 × 10(5) M(-1) s(-1), respectively. The structures of apo TaCypA-1 and the TaCypA-1-CsA complex were determined at 1.25 and 1.20 Å resolution, respectively, using X-ray diffraction. Binding of CsA to the active site of TaCypA-1 did not result in any significant conformational change in the apo TaCypA-1 structure. This is consistent with the crystal structure of the human cyclophilin D-CsA complex reported at 0.96 Å resolution. The TaCypA-1 structure revealed the presence of a divergent loop of seven amino acids (48)KSGKPLH(54) which is a characteristic feature of plant cyclophilins. This study is the first to elucidate the structure of an enzymatically active plant cyclophilin which shows peptidyl-prolyl cis-trans isomerase activity and the presence of a divergent loop.

PubMed: 23519664
DOI: 10.1107/S0907444912051529

Experimental method

X-RAY DIFFRACTION (1.251 Å)