6COK

Structure of the 2nd TOG domain from yeast CLASP protein STU1

Summary for 6COK

• Entry DOI: 10.2210/pdb6cok/pdb
• Descriptor: Protein STU1 (2 entities in total)
• Functional Keywords: heat repeat, single domain, protein binding
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Total number of polymer chains: 1
• Total formula weight: 36861.27

Authors

Majumdar, S.,Rice, L.M. (deposition date: 2018-03-12, release date: 2019-01-23, Last modification date: 2024-03-13)

Primary citation

Majumdar, S.,Kim, T.,Chen, Z.,Munyoki, S.,Tso, S.C.,Brautigam, C.A.,Rice, L.M.
An isolated CLASP TOG domain suppresses microtubule catastrophe and promotes rescue.
Mol. Biol. Cell, 29:1359-1375, 2018

PubMed Abstract: Microtubules are heavily regulated dynamic polymers of αβ-tubulin that are required for proper chromosome segregation and organization of the cytoplasm. Polymerases in the XMAP215 family use arrayed TOG domains to promote faster microtubule elongation. Regulatory factors in the cytoplasmic linker associated protein (CLASP) family that reduce catastrophe and/or increase rescue also contain arrayed TOGs, but how CLASP TOGs contribute to activity is poorly understood. Here, using Saccharomyces cerevisiae Stu1 as a model CLASP, we report structural, biochemical, and reconstitution studies that clarify functional properties of CLASP TOGs. The two TOGs in Stu1 have very different tubulin-binding properties: TOG2 binds to both unpolymerized and polymerized tubulin, and TOG1 binds very weakly to either. The structure of Stu1-TOG2 reveals a CLASP-specific residue that likely confers distinctive tubulin-binding properties. The isolated TOG2 domain strongly suppresses microtubule catastrophe and increases microtubule rescue in vitro, contradicting the expectation that regulatory activity requires an array of TOGs. Single point mutations on the tubulin-binding surface of TOG2 ablate its anti-catastrophe and rescue activity in vitro, and Stu1 function in cells. Revealing that an isolated CLASP TOG can regulate polymerization dynamics without being part of an array provides insight into the mechanism of CLASPs and diversifies the understanding of TOG function.

PubMed: 29851564
DOI: 10.1091/mbc.E17-12-0748

Experimental method

X-RAY DIFFRACTION (1.89 Å)