RT Journal Article SR Electronic T1 Structural and regulatory insights into the glideosome-associated connector from Toxoplasma gondii JF bioRxiv FD Cold Spring Harbor Laboratory SP 2023.01.23.525158 DO 10.1101/2023.01.23.525158 A1 Amit Kumar A1 Oscar Vadas A1 Nicolas Dos Santos Pacheco A1 Xu Zhang A1 Kin Chao A1 Nicolas Darvill A1 Helena Ø. Rasmussen A1 Yingqi Xu A1 Gloria Lin A1 Fisentzos A Stylianou A1 Jan Skov Pedersen A1 Sarah L. Rouse A1 Marc L. Morgan A1 Dominique Soldati-Favre A1 Steve Matthews YR 2023 UL http://biorxiv.org/content/early/2023/01/23/2023.01.23.525158.abstract AB The phylum of Apicomplexa groups intracellular parasites that employ substratedependent gliding motility to invade host cells, egress from the infected cells and cross biological barriers. The glideosome associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface transmembrane adhesins and the efficient transmission of the force generated by myosin translocation of actin to the cell surface substrate. Here, we present the crystal structure of Toxoplasma gondii GAC and reveal a unique, supercoiled armadillo repeat region that adopts a closed ring conformation. Characterisation of the membrane binding interface within the C-terminal PH domain as well as an N-terminal fragment necessary for association with F-actin suggest that GAC adopts multiple conformations. A multi-conformational model for assembly of GAC within the glideosome is proposed.Competing Interest StatementThe authors have declared no competing interest.