5oxf

From Proteopedia

An oligomerised bacterial dynamin pair provides a mechanism for the long range sensing and tethering of membranes

Structural highlights

5oxf is a 4 chain structure with sequence from Campylobacter jejuni. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.94Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

DLP1_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 PubMed

Dynamin-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.

References

↑ Liu J, Noel JK, Low HH. Structural basis for membrane tethering by a bacterial dynamin-like pair. Nat Commun. 2018 Aug 21;9(1):3345. doi: 10.1038/s41467-018-05523-8. PMID:30131557 doi:http://dx.doi.org/10.1038/s41467-018-05523-8
↑ Liu J, Noel JK, Low HH. Structural basis for membrane tethering by a bacterial dynamin-like pair. Nat Commun. 2018 Aug 21;9(1):3345. doi: 10.1038/s41467-018-05523-8. PMID:30131557 doi:http://dx.doi.org/10.1038/s41467-018-05523-8