|
|
| Line 20: |
Line 20: |
| </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3icv ConSurf]. | | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3icv ConSurf]. |
| <div style="clear:both"></div> | | <div style="clear:both"></div> |
| <div style="background-color:#fffaf0;">
| |
| == Publication Abstract from PubMed ==
| |
| Circular permutation of Candida antarctica lipase B yields several enzyme variants with substantially increased catalytic activity. To better understand the structural and functional consequences of protein termini reorganization, we have applied protein engineering and x-ray crystallography to cp283, one of the most active hydrolase variants. Our initial investigation has focused on the role of an extended surface loop, created by linking the native N- and C-termini, on protein integrity. Incremental truncation of the loop partially compensates for observed losses in secondary structure and the permutants' temperature of unfolding. Unexpectedly, the improvements are accompanied by quaternary-structure changes from monomer to dimer. The crystal structures of one truncated variant (cp283 Delta 7) in the apo-form determined at 1.49 A resolution and with a bound phosphonate inhibitor at 1.69 A resolution confirmed the formation of a homodimer by swapping of the enzyme's 35-residue N-terminal region. Separately, the new protein termini at amino acid positions 282/283 convert the narrow access tunnel to the catalytic triad into a broad crevice for accelerated substrate entry and product exit while preserving the native active-site topology for optimal catalytic turnover.
| |
|
| |
| Structural redesign of lipase B from Candida antarctica by circular permutation and incremental truncation.,Qian Z, Horton JR, Cheng X, Lutz S J Mol Biol. 2009 Oct 16;393(1):191-201. Epub 2009 Aug 13. PMID:19683009<ref>PMID:19683009</ref>
| |
|
| |
| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| |
| </div>
| |
| <div class="pdbe-citations 3icv" style="background-color:#fffaf0;"></div>
| |
|
| |
|
| ==See Also== | | ==See Also== |
| *[[Lipase 3D Structures|Lipase 3D Structures]] | | *[[Lipase 3D Structures|Lipase 3D Structures]] |
| == References ==
| |
| <references/>
| |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
