Crystal structure of the collagen prolyl 4-hydroxylase (C-P4H) catalytic domain complexed with PDI: towards a model of the C-P4H α2β2 tetramer

DOI: 10.1016/j.jbc.2022.102614

Authors: Abhinandan V. Murthy (University of Oulu) , Ramita Sulu (University of Oulu) , Andrey Lebedev (Research Complex at Harwell) , Antti M. Salo (University of Oulu) , Kati Korhonen (University of Oulu) , Rajaram Venkatesan (University of Oulu) , Hongmin Tu (University of Oulu) , Ulrich Bergmann (University of Oulu) , Janne Jänis (University of Eastern Finland) , Mikko Laitaoja (University of Eastern Finland) , Lloyd Ruddock (University of Oulu) , Johanna Myllyharju (University of Oulu) , M. Kristian Koski (University of Oulu) , Rik. K. Wierenga (University of Oulu)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Biological Chemistry , VOL 22

State: Published (Approved)
Published: October 2022
Diamond Proposal Number(s): 20001 , 13172 , 19951

Abstract: Collagen prolyl 4-hydroxylases (C-P4H) are α2β2 tetramers, which catalyze the prolyl 4-hydroxylation of procollagen chains, allowing for the formation of the stable triple-helical collagen structure in the endoplasmic reticulum. The C-P4H α-subunit provides the N-terminal dimerization domain, the middle peptide-substrate-binding domain (PSB), and the C-terminal catalytic (CAT) domain, while the β-subunit is identical to the enzyme protein disulfide isomerase (PDI). The structure of the N-terminal part of the α-subunit (N-terminal and PSB domain) is known, but the structures of the PSB-CAT linker region and the CAT domain as well as its mode of assembly with the β/PDI-subunit, are not known. Here we report the crystal structure of the CAT domain of human C-P4H-II complexed with the intact β/PDI-subunit, at 3.8Å resolution. The CAT domain interacts with the a, b’, and a’ domains of the β/PDI-subunit, such that the CAT active site is facing bulk solvent. The structure also shows that the C-P4H-II CAT domain has a unique N-terminal extension, consisting of α-helices and a β-strand, which is the edge strand of its major antiparallel β-sheet. This extra region of the CAT domain interacts tightly with the β/PDI-subunit, showing that the CAT-PDI interface includes an inter-subunit disulfide bridge with the a’ domain and tight hydrophobic interactions with the b’ domain. Using this new structural information, the structure of the mature C-P4H-II α2β2 tetramer is predicted. The model suggests that the CAT active site properties are modulated by α-helices of the N-terminal dimerization domains of both subunits of the α2-dimer.

Subject Areas: Biology and Bio-materials


Instruments: I03-Macromolecular Crystallography , I04-Macromolecular Crystallography , VMXi-Versatile Macromolecular Crystallography in situ

Other Facilities: ID-29 at ESRF; P14 at PETRA III

Added On: 19/10/2022 11:36

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)