Crystal Structure of the Epo1-Bem3 Complex for Bud Growth

• Published in: International journal of molecular sciences Vol. 22; no. 8; p. 3812
• Main Authors: Wang, Jin, Li, Lei, Ming, Zhenhua, Wu, Lijie, Yan, Liming
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.04.2021; MDPI
• Subjects: Actin; Amino Acid Sequence; Amino acids; budding yeast; Carrier Proteins - chemistry; Cdc42 protein; Cell cycle; complex; Crystal structure; Crystallography, X-Ray; Deuterium; Endoplasmic reticulum; Epo1-Bem3; GTPase-Activating Proteins - chemistry; Hydrogen bonds; Hydrogen-deuterium exchange; Interfaces; Magnetic Resonance Spectroscopy; Membrane proteins; Models, Molecular; Molecular structure; Multiprotein Complexes - chemistry; Mutation; polarisome; Protein Binding; Protein Conformation; Protein Multimerization; Proteins; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Ssc2; Structure-Activity Relationship; Triphosphatase; Tubules; polarisome; Ssc2; Epo1-Bem3; budding yeast; complex
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22083812

Tubules of the endoplasmic reticulum (ER) spread into the buds of yeast by an actin-based mechanism and, upon entry, become attached to the polarisome, a proteinaceous micro-compartment below the tip of the bud. The minimal tether between polarisome and cortical ER is formed by a protein complex consisting of Epo1, a member of the polarisome, Scs2, a membrane protein of the ER and Cdc42 guanosine triphosphatase-activating protein Bem3. Here, we report the crystal structure of a complex between Epo1 and Bem3. In addition, we characterize through the hydrogen/deuterium (H/D) exchange assay the interface between Scs2 and Epo1. Our findings provide a first structural insight into the molecular architecture of the link between cortical ER and the polarisome.