1d2f
From Proteopedia
(New page: 200px<br /><applet load="1d2f" size="450" color="white" frame="true" align="right" spinBox="true" caption="1d2f, resolution 2.5Å" /> '''X-RAY STRUCTURE OF MA...) |
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| - | [[Image:1d2f.gif|left|200px]]<br /><applet load="1d2f" size=" | + | [[Image:1d2f.gif|left|200px]]<br /><applet load="1d2f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1d2f, resolution 2.5Å" /> | caption="1d2f, resolution 2.5Å" /> | ||
'''X-RAY STRUCTURE OF MALY FROM ESCHERICHIA COLI: A PYRIDOXAL-5'-PHOSPHATE-DEPENDENT ENZYME ACTING AS A MODULATOR IN MAL GENE EXPRESSION'''<br /> | '''X-RAY STRUCTURE OF MALY FROM ESCHERICHIA COLI: A PYRIDOXAL-5'-PHOSPHATE-DEPENDENT ENZYME ACTING AS A MODULATOR IN MAL GENE EXPRESSION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | MalY represents a bifunctional pyridoxal 5'-phosphate-dependent enzyme | + | MalY represents a bifunctional pyridoxal 5'-phosphate-dependent enzyme acting as a beta-cystathionase and as a repressor of the maltose regulon. Here we present the crystal structures of wild-type and A221V mutant protein. Each subunit of the MalY dimer is composed of a large pyridoxal 5'-phosphate-binding domain and a small domain similar to aminotransferases. The structural alignment with related enzymes identifies residues that are generally responsible for beta-lyase activity and depicts a unique binding mode of the pyridoxal 5'-phosphate correlated with a larger, more flexible substrate-binding pocket. In a screen for MalY mutants with reduced mal repressor properties, mutations occurred in three clusters: I, 83-84; II, 181-189 and III, 215-221, which constitute a clearly distinguished region in the MalY crystal structure far away from the cofactor. The tertiary structure of one of these mutants (A221V) demonstrates that positional rearrangements are indeed restricted to regions I, II and III. Therefore, we propose that a direct protein-protein interaction with MalT, the central transcriptional activator of the maltose system, underlies MalY-dependent repression of the maltose system. |
==About this Structure== | ==About this Structure== | ||
| - | 1D2F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with PLP as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1D2F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PLP:'>PLP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D2F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: small c-terminal domain]] | [[Category: small c-terminal domain]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:12:16 2008'' |
Revision as of 10:12, 21 February 2008
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X-RAY STRUCTURE OF MALY FROM ESCHERICHIA COLI: A PYRIDOXAL-5'-PHOSPHATE-DEPENDENT ENZYME ACTING AS A MODULATOR IN MAL GENE EXPRESSION
Overview
MalY represents a bifunctional pyridoxal 5'-phosphate-dependent enzyme acting as a beta-cystathionase and as a repressor of the maltose regulon. Here we present the crystal structures of wild-type and A221V mutant protein. Each subunit of the MalY dimer is composed of a large pyridoxal 5'-phosphate-binding domain and a small domain similar to aminotransferases. The structural alignment with related enzymes identifies residues that are generally responsible for beta-lyase activity and depicts a unique binding mode of the pyridoxal 5'-phosphate correlated with a larger, more flexible substrate-binding pocket. In a screen for MalY mutants with reduced mal repressor properties, mutations occurred in three clusters: I, 83-84; II, 181-189 and III, 215-221, which constitute a clearly distinguished region in the MalY crystal structure far away from the cofactor. The tertiary structure of one of these mutants (A221V) demonstrates that positional rearrangements are indeed restricted to regions I, II and III. Therefore, we propose that a direct protein-protein interaction with MalT, the central transcriptional activator of the maltose system, underlies MalY-dependent repression of the maltose system.
About this Structure
1D2F is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
X-ray structure of MalY from Escherichia coli: a pyridoxal 5'-phosphate-dependent enzyme acting as a modulator in mal gene expression., Clausen T, Schlegel A, Peist R, Schneider E, Steegborn C, Chang YS, Haase A, Bourenkov GP, Bartunik HD, Boos W, EMBO J. 2000 Mar 1;19(5):831-42. PMID:10698925
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