Structural basis for the broad substrate specificity of the human tyrosylprotein sulfotransferase-1

Shinnosuke Tanaka,Yoichi Sakakibara,Katsuhisa Kurogi,Ming-Cheh Liu,Toshiaki Nishiyori,Hidetaka Kojo,Reo Otsubo,Moe Tsuruta,Yoshimitsu Kakuta,Masahito Suiko

doi:10.1038/s41598-017-07141-8

Shinnosuke Tanaka, Yoichi Sakakibara + Show 8 more

Open Access

https://doi.org/10.1038/s41598-017-07141-8

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Abstract

Tyrosylprotein sulfotransferases (TPSTs) are enzymes that catalyze post-translational tyrosine sulfation of proteins. In humans, there are only two TPST isoforms, designated TPST1 and TPST2. In a previous study, we reported the crystal structure of TPST2, which revealed the catalytic mechanism of the tyrosine sulfation reaction. However, detailed molecular mechanisms underlying how TPSTs catalyse a variety of substrate proteins with different efficiencies and how TPSTs catalyze the sulfation of multiple tyrosine residues in a substrate protein remain unresolved. Here, we report two crystal structures of the human TPST1 complexed with two substrate peptides that are catalysed by human TPST1 with significantly different efficiencies. The distinct binding modes found in the two complexes provide insight into the sulfation mechanism for these substrates. The present study provides valuable information describing the molecular mechanism of post-translational protein modifications catalysed by TPSTs.

Highlights

Tyrosine sulfation, first discovered in bovine fibrinogen, is a major post-translational modification[1] that occurs widely among proteins in multicellular eukaryotic organisms[2, 3]
Kinetic analysis showed that human TPST1 displayed Km values of 7.67 μM and 6.52 × 102 μM for C4P5Y5 and the gastrin peptide, respectively
Crystal structures of human TPST2 and kinetic constants indicated that Asp residue at the −1 position and the acidic residue at the +1 position are major determinants of the Km values[26]

Summary

Introduction

First discovered in bovine fibrinogen, is a major post-translational modification[1] that occurs widely among proteins in multicellular eukaryotic organisms[2, 3]. Sulfation of tyrosine residues is thought to play important roles in various functional modifications that are controlled by TPSTs. We recently solved the crystal structure of human TPST2 complexed with PAP and a substrate peptide (designated C4P5Y3, Fig. 1) derived from complement C4 at 1.9 Å resolution[26] (Supplementary Fig. S2). The mechanism underlying how human TPSTs may accommodate a variety of substrate proteins with different efficiencies, how human TPSTs recognise multiple tyrosine residues in substrate proteins remains unclear. Structural information derived from the current study reveals the mechanism underlying how human TPSTs recognise a variety of substrate proteins with different efficiencies and how human TPSTs recognise multiple tyrosine residues in a substrate protein

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