Structural analysis of the LDL receptor-interacting FERM domain in the E3 ubiquitin ligase IDOL reveals an obscured substrate-binding site.

Hepatic abundance of the low-density lipoprotein receptor (LDLR) is a critical determinant of circulating plasma LDL cholesterol levels and hence development of coronary artery disease. The sterol-responsive E3 ubiquitin ligase inducible degrader of the LDLR (IDOL) specifically promotes ubiquitination and subsequent lysosomal degradation of the LDLR and thus controls cellular LDL uptake. IDOL contains an extended N-terminal FERM (4.

The nucleotide-bound/substrate-bound conformation of the Mycoplasma genitalium DnaK chaperone.

Hsp70 chaperones keep protein homeostasis facilitating the response of organisms to changes in external and internal conditions. Hsp70s have two domains-nucleotide binding domain (NBD) and substrate binding domain (SBD)-connected by a conserved hydrophobic linker. Functioning of Hsp70s depend on tightly regulated cycles of ATP hydrolysis allosterically coupled, often together with cochaperones, to the binding/release of peptide substrates.

Structure-Guided Mutations in the Terminal Organelle Protein MG491 Cause Major Motility and Morphologic Alterations on Mycoplasma genitalium.

The emergent human pathogen Mycoplasma genitalium, with one of the smallest genomes among cells capable of growing in axenic cultures, presents a flask-shaped morphology due to a protrusion of the cell membrane, known as the terminal organelle, that is involved in cell adhesion and motility and is an important virulence factor of this microorganism. The terminal organelle is supported by a cytoskeleton complex of about 300 nm in length that includes three substructures: the terminal button, the rod and the wheel complex. The crystal structure of the MG491 protein, a proposed component of the wheel complex, has been determined at ~3 Å resolution.

A major determinant for gliding motility in Mycoplasma genitalium: the interaction between the terminal organelle proteins MG200 and MG491.

Several mycoplasmas, such as the emergent human pathogen Mycoplasma genitalium, developed a complex polar structure, known as the terminal organelle (TO), responsible for a new type of cellular motility, which is involved in a variety of cell functions: cell division, adherence to host cells, and virulence. The TO cytoskeleton is organized as a multisubunit dynamic motor, including three main ultrastructures: the terminal button, the electrodense core, and the wheel complex. Here, we describe the interaction between MG200 and MG491, two of the main components of the TO wheel complex that connects the TO with the cell body and the cell membrane.

The EAGR box structure: a motif involved in mycoplasma motility.

Mycoplasma genitalium is an emerging human pathogen with the smallest genome found among self-replicating organisms. M. genitalium presents a complex cytoskeleton with a differentiated protrusion known as the terminal organelle.