1m6e
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1m6e.jpg|left|200px]] | [[Image:1m6e.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1m6e", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_1m6e| PDB=1m6e | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''CRYSTAL STRUCTURE OF SALICYLIC ACID CARBOXYL METHYLTRANSFERASE (SAMT)''' | '''CRYSTAL STRUCTURE OF SALICYLIC ACID CARBOXYL METHYLTRANSFERASE (SAMT)''' | ||
| Line 31: | Line 28: | ||
[[Category: Yang, Y.]] | [[Category: Yang, Y.]] | ||
[[Category: Zubieta, C.]] | [[Category: Zubieta, C.]] | ||
| - | [[Category: | + | [[Category: Protein-small molecule complex]] |
| - | [[Category: | + | [[Category: Rossmann fold]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:41:27 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 21:41, 2 May 2008
CRYSTAL STRUCTURE OF SALICYLIC ACID CARBOXYL METHYLTRANSFERASE (SAMT)
Overview
Recently, a novel family of methyltransferases was identified in plants. Some members of this newly discovered and recently characterized methyltransferase family catalyze the formation of small-molecule methyl esters using S-adenosyl-L-Met (SAM) as a methyl donor and carboxylic acid-bearing substrates as methyl acceptors. These enzymes include SAMT (SAM:salicylic acid carboxyl methyltransferase), BAMT (SAM:benzoic acid carboxyl methyltransferase), and JMT (SAM:jasmonic acid carboxyl methyltransferase). Moreover, other members of this family of plant methyltransferases have been found to catalyze the N-methylation of caffeine precursors. The 3.0-A crystal structure of Clarkia breweri SAMT in complex with the substrate salicylic acid and the demethylated product S-adenosyl-L-homocysteine reveals a protein structure that possesses a helical active site capping domain and a unique dimerization interface. In addition, the chemical determinants responsible for the selection of salicylic acid demonstrate the structural basis for facile variations of substrate selectivity among functionally characterized plant carboxyl-directed and nitrogen-directed methyltransferases and a growing set of related proteins that have yet to be examined biochemically. Using the three-dimensional structure of SAMT as a guide, we examined the substrate specificity of SAMT by site-directed mutagenesis and activity assays against 12 carboxyl-containing small molecules. Moreover, the utility of structural information for the functional characterization of this large family of plant methyltransferases was demonstrated by the discovery of an Arabidopsis methyltransferase that is specific for the carboxyl-bearing phytohormone indole-3-acetic acid.
About this Structure
1M6E is a Single protein structure of sequence from Clarkia breweri. Full crystallographic information is available from OCA.
Reference
Structural basis for substrate recognition in the salicylic acid carboxyl methyltransferase family., Zubieta C, Ross JR, Koscheski P, Yang Y, Pichersky E, Noel JP, Plant Cell. 2003 Aug;15(8):1704-16. PMID:12897246 Page seeded by OCA on Sat May 3 00:41:27 2008
