6HRC

Outward-facing PglK with ATPgammaS bound

Summary for 6HRC

• Entry DOI: 10.2210/pdb6hrc/pdb
• Related: 5C73 5C76 5C78 5NBD
• Descriptor: WlaB protein, PHOSPHOTHIOPHOSPHORIC ACID-ADENYLATE ESTER, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: abc transporter, transport protein
• Biological source: Campylobacter jejuni
• Total number of polymer chains: 4
• Total formula weight: 260380.08

Authors

Perez, C.,Locher, K.P. (deposition date: 2018-09-26, release date: 2019-03-06, Last modification date: 2024-01-24)

Primary citation

Perez, C.,Mehdipour, A.R.,Hummer, G.,Locher, K.P.
Structure of Outward-Facing PglK and Molecular Dynamics of Lipid-Linked Oligosaccharide Recognition and Translocation.
Structure, 27:669-678.e5, 2019

PubMed Abstract: PglK is a lipid-linked oligosaccharide (LLO) flippase essential for asparagine-linked protein glycosylation in Campylobacter jejuni. Previously we have proposed a non-alternating-access LLO translocation mechanism, where postulated outward-facing states play a primary role. To investigate this unusual mechanistic proposal, we have determined a high-resolution structure of PglK that displays an outward semi-occluded state with the two nucleotide binding domains forming an asymmetric closed dimer with two bound ATPγS molecules. Based on this structure, we performed extensive molecular dynamics simulations to investigate LLO recognition and flipping. Our results suggest that PglK may employ a "substrate-hunting" mechanism to locally increase the LLO concentration and facilitate its jump into the translocation pathway, for which sugars from the LLO head group are essential. We further conclude that the release of LLO to the outside occurs before ATP hydrolysis and is followed by the closing of the periplasmic cavity of PglK.

PubMed: 30799077
DOI: 10.1016/j.str.2019.01.013

Experimental method

X-RAY DIFFRACTION (3.3 Å)