Structural basis for substrate specificity and regulation of nucleotide sugar transporters in the lipid bilayer

• Published in: Nature communications 2019-10, Vol.10 (1), p.4657-10, Article 4657
• Main Authors: Parker, Joanne L., Corey, Robin A., Stansfeld, Phillip J., Newstead, Simon
• Format: Article
• Language: English
• Subjects: 119/118; 631/45/535/1266; 631/535; 82/83; Binding Sites; Biochemical analysis; Crystal structure; Dimers; Endoplasmic reticulum; Eukaryotes; GDP-mannose; GDP-mannose transporter; Glycosylation; Golgi apparatus; Guanosine diphosphate; Guanosine Monophosphate - chemistry; Guanosine Monophosphate - metabolism; Humanities and Social Sciences; Lipid bilayers; Lipid Bilayers - metabolism; Lipids; Mannose; Membrane Transport Proteins - chemistry; Membrane Transport Proteins - metabolism; Membranes; Models, Chemical; Molecular dynamics; Monosaccharides; multidisciplinary; Nucleotides; Organelles; Protein Domains; Regulatory sequences; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - metabolism; Science; Science (multidisciplinary); Substrate Specificity; Substrates; Sugar; Transport; Yeast; Yeasts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-12673-w

Nucleotide sugars are the activated form of monosaccharides used by glycosyltransferases during glycosylation. In eukaryotes the SLC35 family of solute carriers are responsible for their selective uptake into the Endoplasmic Reticulum or Golgi apparatus. The structure of the yeast GDP-mannose transporter, Vrg4, revealed a requirement for short chain lipids and a marked difference in transport rate between the nucleotide sugar and nucleoside monophosphate, suggesting a complex network of regulatory elements control transport into these organelles. Here we report the crystal structure of the GMP bound complex of Vrg4, revealing the molecular basis for GMP recognition and transport. Molecular dynamics, combined with biochemical analysis, reveal a lipid mediated dimer interface and mechanism for coordinating structural rearrangements during transport. Together these results provide further insight into how SLC35 family transporters function within the secretory pathway and sheds light onto the role that membrane lipids play in regulating transport across the membrane. In eukaryotes the SLC35 family of solute carriers mediate the selective uptake of nucleotide sugars from the cytoplasm into the Endoplasmic Reticulum or Golgi. Here authors report the crystal structure of the yeast GDP-mannose transporter, Vrg4, bound to guanine monophosphate (GMP) revealing the molecular basis for GMP recognition and transport.