2qua: Difference between revisions

==Overview==

Lipase LipA from Serratia marcescens is a 613-amino acid enzyme belonging, to family I.3 of lipolytic enzymes that has an important biotechnological, application in the production of a chiral precursor for the coronary, vasodilator diltiazem. Like other family I.3 lipases, LipA is secreted by, Gram-negative bacteria via a type I secretion system and possesses 13, copies of a calcium binding tandem repeat motif, GGXGXDXUX (U, hydrophobic, amino acids), in the C-terminal part of the polypeptide chain. The 1.8-A, crystal structure of LipA reveals a close relation to eukaryotic lipases, whereas family I.1 and I.2 enzymes appear to be more distantly related., Interestingly, the structure shows for the N-terminal lipase domain a, variation on the canonical alpha/beta hydrolase fold in an open, conformation, where the putative lid helix is anchored by a Ca(2+) ion, essential for activity. Another novel feature observed in this lipase, structure is the presence of a helical hairpin additional to the putative, lid helix that exposes a hydrophobic surface to the aqueous medium and, might function as an additional lid. The tandem repeats form two separated, parallel beta-roll domains that pack tightly against each other., Variations of the consensus sequence of the tandem repeats within the, second beta-roll result in an asymmetric Ca(2+) binding on only one side, of the roll. The analysis of the properties of the beta-roll domains, suggests an intramolecular chaperone function.

==About this Structure==

2QUA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Triacylglycerol_lipase Triacylglycerol lipase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.3 3.1.1.3] Known structural/functional Sites: <scene name='pdbsite=AC1:Ca Binding Site For Residue A 614'>AC1</scene>, <scene name='pdbsite=AC2:Ca Binding Site For Residue A 615'>AC2</scene>, <scene name='pdbsite=AC3:Ca Binding Site For Residue A 616'>AC3</scene>, <scene name='pdbsite=AC4:Ca Binding Site For Residue A 617'>AC4</scene>, <scene name='pdbsite=AC5:Ca Binding Site For Residue A 618'>AC5</scene>, <scene name='pdbsite=AC6:Ca Binding Site For Residue A 619'>AC6</scene>, <scene name='pdbsite=AC7:Ca Binding Site For Residue A 620'>AC7</scene> and <scene name='pdbsite=AC8:Ca Binding Site For Residue A 621'>AC8</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QUA OCA].

 

A calcium-gated lid and a large beta-roll sandwich are revealed by the crystal structure of extracellular lipase from Serratia marcescens., Meier R, Drepper T, Svensson V, Jaeger KE, Baumann U, J Biol Chem. 2007 Oct 26;282(43):31477-83. Epub 2007 Aug 28. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17728256 17728256]

[[Category: Baumann, U.]]

[[Category: Meier, R.]]

[[Category: CA]]