PDBsum entry 1tcc

Hydrolase(carboxylic esterase)

PDB id: 1tcc

Contents

Protein chains

317 a.a.

Ligands

NAG-NAG

BOG

Waters ×159

References listed in PDB file

Key reference

Title

The sequence, Crystal structure determination and refinement of two crystal forms of lipase b from candida antarctica.

Authors

J.Uppenberg, M.T.Hansen, S.Patkar, T.A.Jones.

Ref.

Structure, 1994, 2, 293-308. [DOI no: 10.1016/S0969-2126(00)00031-9]

PubMed id

8087556

Abstract

BACKGROUND: Lipases constitute a family of enzymes that hydrolyze triglycerides. They occur in many organisms and display a wide variety of substrate specificities. In recent years, much progress has been made towards explaining the mechanism of these enzymes and their ability to hydrolyze their substrates at an oil-water interface. RESULTS: We have determined the DNA and amino acid sequences for lipase B from the yeast Candida antarctica. The primary sequence has no significant homology to any other known lipase and deviates from the consensus sequence around the active site serine that is found in other lipases. We have determined the crystal structure of this enzyme using multiple isomorphous replacement methods for two crystal forms. Models for the orthorhombic and monoclinic crystal forms of the enzyme have been refined to 1.55 A and 2.1 A resolution, respectively. Lipase B is an alpha/beta type protein that has many features in common with previously determined lipase structures and other related enzymes. In the monoclinic crystal form, lipid-like molecules, most likely beta-octyl glucoside, can be seen close to the active site. The behaviour of these lipid molecules in the crystal structure has been studied at different pH values. CONCLUSION: The structure of Candida antarctica lipase B shows that the enzyme has a Ser-His-Asp catalytic triad in its active site. The structure appears to be in an 'open' conformation with a rather restricted entrance to the active site. We believe that this accounts for the substrate specificity and high degree of stereospecificity of this lipase.

Figure 2.
Figure 2. Stereo drawing of the Cα trace of CALB. The structure is coloured red at the amino terminus, then orange, light green, dark green, pale blue, and finally dark blue at the carboxyl terminus. Figure 2. Stereo drawing of the Cα trace of CALB. The structure is coloured red at the amino terminus, then orange, light green, dark green, pale blue, and finally dark blue at the carboxyl terminus.

Figure 7.
Figure 7. A stereo picture of the RML-phosphonate inhibitor complex and an alignment with CALB in this region. All residues believed to make up the oxyanion hole have a similar conformation in the two enzymes. Hypothetical hydrogen bonds from the inhibitor to CALB are indicated by dashed lines. RML is shown in black, CALB in the colour scheme used for Figure 5. Figure 7. A stereo picture of the RML-phosphonate inhibitor complex and an alignment with CALB in this region. All residues believed to make up the oxyanion hole have a similar conformation in the two enzymes. Hypothetical hydrogen bonds from the inhibitor to CALB are indicated by dashed lines. RML is shown in black, CALB in the colour scheme used for [3]Figure 5.

The above figures are reprinted by permission from Cell Press: Structure (1994, 2, 293-308) copyright 1994.

Secondary reference #1

Title

Crystallization and preliminary X-Ray studies of lipase b from candida antarctica.

Authors

J.Uppenberg, S.Patkar, T.Bergfors, T.A.Jones.

Ref.

J Mol Biol, 1994, 235, 790-792.

PubMed id

8289302