6UQQ

Crystal Structure of GTPase Domain of Human Septin 7 / Septin 3 T282Y Heterocomplex

Summary for 6UQQ

• Entry DOI: 10.2210/pdb6uqq/pdb
• Related: 6UPA 6UPQ 6UPR
• Descriptor: Septin-7, Neuronal-specific septin-3, GUANOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: cytoskeleton protein, septin, structural protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 4
• Total formula weight: 135124.67

Authors

Bragnara, G.,Pereira, H.M.,Brandao-Neto, J.,Araujo, A.P.U.,Garratt, R.C. (deposition date: 2019-10-21, release date: 2020-09-23, Last modification date: 2023-10-11)

Primary citation

Rosa, H.V.D.,Leonardo, D.A.,Brognara, G.,Brandao-Neto, J.,D'Muniz Pereira, H.,Araujo, A.P.U.,Garratt, R.C.
Molecular Recognition at Septin Interfaces: The Switches Hold the Key.
J.Mol.Biol., 432:5784-5801, 2020

PubMed Abstract: The assembly of a septin filament requires that homologous monomers must distinguish between one another in establishing appropriate interfaces with their neighbors. To understand this phenomenon at the molecular level, we present the first four crystal structures of heterodimeric septin complexes. We describe in detail the two distinct types of G-interface present within the octameric particles, which must polymerize to form filaments. These are formed between SEPT2 and SEPT6 and between SEPT7 and SEPT3, and their description permits an understanding of the structural basis for the selectivity necessary for correct filament assembly. By replacing SEPT6 by SEPT8 or SEPT11, it is possible to rationalize Kinoshita's postulate, which predicts the exchangeability of septins from within a subgroup. Switches I and II, which in classical small GTPases provide a mechanism for nucleotide-dependent conformational change, have been repurposed in septins to play a fundamental role in molecular recognition. Specifically, it is switch I which holds the key to discriminating between the two different G-interfaces. Moreover, residues which are characteristic for a given subgroup play subtle, but pivotal, roles in guaranteeing that the correct interfaces are formed.

PubMed: 32910969
DOI: 10.1016/j.jmb.2020.09.001

Experimental method

X-RAY DIFFRACTION (2.75 Å)