1B5L

OVINE INTERFERON TAU

Summary for 1B5L

• Entry DOI: 10.2210/pdb1b5l/pdb
• Descriptor: INTERFERON TAU, SULFATE ION (3 entities in total)
• Functional Keywords: cytokine
• Biological source: Pichia pastoris
• Total number of polymer chains: 1
• Total formula weight: 20127.81

Authors

Radhakrishnan, R.,Walter, L.J.,Subramaniam, P.S.,Johnson, H.J.,Walter, M.R. (deposition date: 1999-01-07, release date: 1999-05-18, Last modification date: 2024-10-30)

Primary citation

Radhakrishnan, R.,Walter, L.J.,Subramaniam, P.S.,Johnson, H.M.,Walter, M.R.
Crystal structure of ovine interferon-tau at 2.1 A resolution.
J.Mol.Biol., 286:151-162, 1999

PubMed Abstract: Ovine interferon-tau (ovIFN-tau) is a pregnancy recognition hormone required for normal embryonic development in sheep. In addition to its novel role in reproductive physiology, ovIFN-tau displays antiviral and antiproliferative activities similar to the IFN-alpha subtypes. To probe the structural basis for its unique activity profile, the crystal structure of ovIFN-tau has been determined at 2.1 A resolution. The fold of ovIFN-tau is similar to the previously determined crystal structures of human IFN-alpha2b and human and murine IFN-beta, which each contain five alpha-helices. Comparison of ovIFN-tau with huIFN-alpha2b, huIFN-beta, and muIFN-beta reveals unexpected structural differences that occur in regions of considerable sequence identity. Specifically, main-chain differences up to 11 A occur for residues in helix A, the AB loop, helix B, and the BC loop. Furthermore, these regions are known to be important for receptor binding and biological activity. Of particular interest, a buried ion pair is observed in ovIFN-tau between Glu71 and Arg145 which displaces a conserved tryptophan residue (Trp77) from the helical bundle core. This ion pair represents a major change in the core of ovIFN-tau compared to huIFN-alpha2b. Based on amino acid sequence comparisons, these ovIFN-tau structural features may be conserved in several human IFN-alpha subtypes and IFN-omega. The structure identifies potential problems in interpreting site-directed mutagenesis data on the human IFN-alpha family that consists of 12 proteins.

PubMed: 9931256
DOI: 10.1006/jmbi.1998.2480

Experimental method

X-RAY DIFFRACTION (2.1 Å)