Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Feb 20;474(5):751-769.
doi: 10.1042/BCJ20161000.

Assembly of the elongated collagen prolyl 4-hydroxylase α2β2 heterotetramer around a central α2 dimer

M Kristian Koski  1 , Jothi Anantharajan  1 , Petri Kursula  1   2 , Prathusha Dhavala  1 , Abhinandan V Murthy  1 , Ulrich Bergmann  1 , Johanna Myllyharju  3 , Rik K Wierenga  4
Affiliations

Assembly of the elongated collagen prolyl 4-hydroxylase α2β2 heterotetramer around a central α2 dimer

M Kristian Koski et al. Biochem J. .

Abstract

Collagen prolyl 4-hydroxylase (C-P4H), an α2β2 heterotetramer, is a crucial enzyme for collagen synthesis. The α-subunit consists of an N-terminal dimerization domain, a central peptide substrate-binding (PSB) domain, and a C-terminal catalytic (CAT) domain. The β-subunit [also known as protein disulfide isomerase (PDI)] acts as a chaperone, stabilizing the functional conformation of C-P4H. C-P4H has been studied for decades, but its structure has remained elusive. Here, we present a three-dimensional small-angle X-ray scattering model of the entire human C-P4H-I heterotetramer. C-P4H is an elongated, bilobal, symmetric molecule with a length of 290 Å. The dimerization domains from the two α-subunits form a protein-protein dimer interface, assembled around the central antiparallel coiled-coil interface of their N-terminal α-helices. This region forms a thin waist in the bilobal tetramer. The two PSB/CAT units, each complexed with a PDI/β-subunit, form two bulky lobes pointing outward from this waist region, such that the PDI/β-subunits locate at the far ends of the βααβ complex. The PDI/β-subunit interacts extensively with the CAT domain. The asymmetric shape of two truncated C-P4H-I variants, also characterized in the present study, agrees with this assembly. Furthermore, data from these truncated variants show that dimerization between the α-subunits has an important role in achieving the correct PSB-CAT assembly competent for catalytic activity. Kinetic assays with various proline-rich peptide substrates and inhibitors suggest that, in the competent assembly, the PSB domain binds to the procollagen substrate downstream from the CAT domain.

Keywords: 2-oxoglutarate dioxygenase; collagen biosynthesis; extracellular matrix proteins; multidomain assembly; prolyl hydroxylase; small-angle X-ray scattering.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

MeSH terms

LinkOut - more resources