1ZWX

Crystal Structure of SmcL

Summary for 1ZWX

• Entry DOI: 10.2210/pdb1zwx/pdb
• Descriptor: sphingomyelinase-c, PHOSPHATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: dnase1-like fold, beta-hairpin, hydrolase
• Biological source: Listeria ivanovii
• Cellular location: Secreted: Q9RLV9
• Total number of polymer chains: 1
• Total formula weight: 34689.51

Authors

Openshaw, A.E.A.,Race, P.R.,Monzo, H.J.,Vasquez-Boland, J.A.,Banfield, M.J. (deposition date: 2005-06-06, release date: 2005-08-16, Last modification date: 2024-02-14)

Primary citation

Openshaw, A.E.A.,Race, P.R.,Monzo, H.J.,Vasquez-Boland, J.A.,Banfield, M.J.
Crystal structure of SmcL, a bacterial neutral sphingomyelinase C from Listeria.
J.Biol.Chem., 280:35011-35017, 2005

PubMed Abstract: Sphingomyelinases C are enzymes that catalyze the hydrolysis of sphingomyelin in biological membranes to ceramide and phosphorylcholine. Various pathogenic bacteria produce secreted neutral sphingomyelinases C that act as membrane-damaging virulence factors. Mammalian neutral sphingomyelinases C, which display sequence homology to the bacterial enzymes, are involved in sphingolipid metabolism and signaling. This article describes the first structure to be determined for a member of the neutral sphingomyelinase C family, SmcL, from the intracellular bacterial pathogen Listeria ivanovii. The structure has been refined to 1.9-A resolution with phases derived by single isomorphous replacement with anomalous scattering techniques from a single iridium derivative. SmcL adopts a DNase I-like fold, and is the first member of this protein superfamily to have its structure determined that acts as a phospholipase. The structure reveals several unique features that adapt the protein to its phospholipid substrate. These include large hydrophobic beta-hairpin and hydrophobic loops surrounding the active site that may bind and penetrate the lipid bilayer to position sphingomyelin in a catalytically competent position. The structure also provides insight into the proposed general base/acid catalytic mechanism, in which His-325 and His-185 play key roles.

PubMed: 16093240
DOI: 10.1074/jbc.M506800200

Experimental method

X-RAY DIFFRACTION (1.9 Å)