A key piece of the puzzle: The central tetramer of the Saccharomyces cerevisiae septin protofilament and its implications for self-assembly

Silva, Rafael Marques da; Saladino, Giovanna Christe dos Reis; Leonardo, D.A.; Pereira, H.M.; Sculaccio, Susana Andréa; Araújo, Ana Paula Ulian de; Garratt, R.C.

doi:10.1016/j.jsb.2023.107983

Cited by 5 publications

(10 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our approach was independently corroborated by the recently published experimental structure of the Cdc10-Cdc10 interface 28 . The root mean deviation (RMSD-Cα) between the predicted and experimentally solved interfaces was below 1.5 Å.…”

Section: Discussionsupporting

confidence: 58%

See 1 more Smart Citation

The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity

Grupp,

Denkhaus,

Gerhardt

et al. 2024

Commun Biol

View full text Add to dashboard Cite

The septins of the yeast Saccharomyces cerevisiae assemble into hetero-octameric rods by alternating interactions between neighboring G-domains or N- and C-termini, respectively. These rods polymerize end to end into apolar filaments, forming a ring beneath the prospective new bud that expands during the cell cycle into an hourglass structure. The hourglass finally splits during cytokinesis into a double ring. Understanding these transitions as well as the plasticity of the higher order assemblies requires a detailed knowledge of the underlying structures. Here we present the first X-ray crystal structure of a tetrameric Shs1-Cdc12-Cdc3-Cdc10 complex at a resolution of 3.2 Å. Close inspection of the NC-interfaces of this and other septin structures reveals a conserved contact motif that is essential for NC-interface integrity of yeast and human septins in vivo and in vitro. Using the tetrameric structure in combination with AlphaFold-Multimer allowed us to propose a model of the octameric septin rod.

show abstract

Section: Discussionsupporting

confidence: 58%

“…During the preparation of this manuscript, the crystal structure of a Cdc3-10-10-3 tetramer became available (PDB-ID 8SGD) 28 . This structure covers the central Cdc10-Cdc10 interface.…”

Section: Resultsmentioning

confidence: 99%

The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity

Grupp,

Denkhaus,

Gerhardt

et al. 2024

Commun Biol

View full text Add to dashboard Cite

show abstract

“…In yeasts with a GTPase-dead Cdc3 homolog, instead of the highly-conserved trans loop 1 His, the Cdc10 homolog instead has Lys, which we proposed favors interaction between Cdc10•GDP and Cdc3•GTP ( Johnson et al, 2020 ). Satisfyingly, recent crystal structures of the S. cerevisiae Cdc3–Cdc10 G heterodimer show that Cdc10 Lys155 directly contacts the γ phosphate of GTP in the Cdc3 pocket ( Marques da Silva et al, 2023 ). Reciprocally, the trans loop 1 His in Cdc3 contacts the β phosphate of GDP in Cdc10’s pocket ( Marques da Silva et al, 2023 ).…”

Section: Introductionmentioning

confidence: 99%

“…Satisfyingly, recent crystal structures of the S. cerevisiae Cdc3–Cdc10 G heterodimer show that Cdc10 Lys155 directly contacts the γ phosphate of GTP in the Cdc3 pocket ( Marques da Silva et al, 2023 ). Reciprocally, the trans loop 1 His in Cdc3 contacts the β phosphate of GDP in Cdc10’s pocket ( Marques da Silva et al, 2023 ). These examples illustrate how changes in individual amino acids correlate with distinct nucleotides bound within the septin G dimer interface.…”

Section: Introductionmentioning

confidence: 99%

“…These examples illustrate how changes in individual amino acids correlate with distinct nucleotides bound within the septin G dimer interface. Comparisons of the recent Cdc3–Cdc10 structures to heterodimers involving human pseudoGTPases revealed another example (coordinating a G3 Gly with γ phosphate using a water molecule versus a G1 Asp sidechain) of how the pocket of the pseudoGTPase changed in distinct ways in parallel evolutionary trajectories to accommodate γ phosphate as a permanent resident ( Marques da Silva et al, 2023 ). Here we explore other examples of deviation within the canonical components of the septin G interface and discuss how they may relate to the evolution of septin pseudoGTPases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evolutionary degeneration of septins into pseudoGTPases: impacts on a hetero-oligomeric assembly interface

Hussain,

Nguyen,

Reigan

et al. 2023

Front. Cell Dev. Biol.

View full text Add to dashboard Cite

The septin family of eukaryotic proteins comprises distinct classes of sequence-related monomers that associate in a defined order into linear hetero-oligomers, which are capable of polymerizing into cytoskeletal filaments. Like actin and ⍺ and β tubulin, most septin monomers require binding of a nucleotide at a monomer-monomer interface (the septin “G” interface) for assembly into higher-order structures. Like ⍺ and β tubulin, where GTP is bound by both subunits but only the GTP at the ⍺–β interface is subject to hydrolysis, the capacity of certain septin monomers to hydrolyze their bound GTP has been lost during evolution. Thus, within septin hetero-oligomers and filaments, certain monomers remain permanently GTP-bound. Unlike tubulins, loss of septin GTPase activity–creating septin “pseudoGTPases”—occurred multiple times in independent evolutionary trajectories, accompanied in some cases by non-conservative substitutions in highly conserved residues in the nucleotide-binding pocket. Here, we used recent septin crystal structures, AlphaFold-generated models, phylogenetics and in silico nucleotide docking to investigate how in some organisms the septin G interface evolved to accommodate changes in nucleotide occupancy. Our analysis suggests that yeast septin monomers expressed only during meiosis and sporulation, when GTP is scarce, are evolving rapidly and might not bind GTP or GDP. Moreover, the G dimerization partners of these sporulation-specific septins appear to carry compensatory changes in residues that form contacts at the G interface to help retain stability despite the absence of bound GDP or GTP in the facing subunit. During septin evolution in nematodes, apparent loss of GTPase activity was also accompanied by changes in predicted G interface contacts. Overall, our observations support the conclusion that the primary function of nucleotide binding and hydrolysis by septins is to ensure formation of G interfaces that impose the proper subunit-subunit order within the hetero-oligomer.

show abstract

Structural Insights into Ciona intestinalis Septins: Complexes Suggest a Mechanism for Nucleotide-dependent Interfacial Cross-talk

Mendonça,

Morais,

Ciol

et al. 2024

Journal of Molecular Biology

View full text Add to dashboard Cite

A key piece of the puzzle: The central tetramer of the Saccharomyces cerevisiae septin protofilament and its implications for self-assembly

Cited by 5 publications

References 54 publications

The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity

The structure of a tetrameric septin complex reveals a hydrophobic element essential for NC-interface integrity

Evolutionary degeneration of septins into pseudoGTPases: impacts on a hetero-oligomeric assembly interface

Structural Insights into Ciona intestinalis Septins: Complexes Suggest a Mechanism for Nucleotide-dependent Interfacial Cross-talk

Contact Info

Product

Resources

About