5oxf
From Proteopedia
An oligomerised bacterial dynamin pair provides a mechanism for the long range sensing and tethering of membranes
Structural highlights
FunctionDLP1_CAMJJ The heterotetrameric DLP1(2)-DLP2(2) complex tethers liposomes and may mediate their fusion. Initial binding is probably mediated by DLP1, while DLP2 couples DLP1 subunits and increases the effective reach of the complex up to 45 nm. The role of the nucleotide is unknown. This subunit alone weakly binds to liposomes; GTP, GDP, GMPPCP and GMPPNP do not change heterotetramer binding. Tetramerization is required for GTPase activity, suggesting the GTPase domains (dynamin-type G) from DLP1 and DLP2 must dimerize to reconstitute the GTPase active site.[1] Publication Abstract from PubMedDynamin-like proteins (DLPs) are large GTPases that restructure membrane. DLPs such as the mitofusins form heterotypic oligomers between isoform pairs that bridge and fuse opposing membranes. In bacteria, heterotypic oligomerisation may also be important for membrane remodelling as most DLP genes are paired within operons. How DLPs tether opposing membranes is unknown. Here we show the crystal structure of a DLP heterotypic pair from the pathogen Campylobacter jejuni. A 2:2 stoichiometric tetramer is observed where heterodimers, conjoined by a random coil linker, assemble back-to-back to form a tripartite DLP chain with extreme flexibility. In vitro, tetramerisation triggers GTPase activity and induces lipid binding. Liposomes are readily tethered and form tubes at high tetramer concentration. Our results provide a direct mechanism for the long-range binding and bridging of opposing membranes by a bacterial DLP pair. They also provide broad mechanistic and structural insights that are relevant to other heterotypic DLP complexes. Structural basis for membrane tethering by a bacterial dynamin-like pair.,Liu J, Noel JK, Low HH Nat Commun. 2018 Aug 21;9(1):3345. doi: 10.1038/s41467-018-05523-8. PMID:30131557[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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