Crystal Structure of the K246R Mutant of Aspartate Semialdehyde Dehydrogenase from Haemophilus influenzaeCrystal Structure of the K246R Mutant of Aspartate Semialdehyde Dehydrogenase from Haemophilus influenzae

Structural highlights

1pu2 is a 1 chain structure with sequence from Haemophilus influenzae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.06Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

DHAS_HAEIN Catalyzes the NADPH-dependent formation of L-aspartate-semialdehyde (L-ASA) by the reductive dephosphorylation of L-aspartyl-4-phosphate.[1]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The reversible dephosphorylation of beta-aspartyl phosphate to L-aspartate-beta-semialdehyde (ASA) in the aspartate biosynthetic pathway is catalyzed by aspartate-beta-semialdehyde dehydrogenase (ASADH). The product of this reaction is a key intermediate in the biosynthesis of diaminopimelic acid, an integral component of bacterial cell walls and a metabolic precursor of lysine and also a precursor in the biosynthesis of threonine, isoleucine and methionine. The structures of selected Haemophilus influenzae ASADH mutants were determined in order to evaluate the residues that are proposed to interact with the substrates ASA or phosphate. The substrate Km values are not altered by replacement of either an active-site arginine (Arg270) with a lysine or a putative phosphate-binding group (Lys246) with an arginine. However, the interaction of phosphate with the enzyme is adversely affected by replacement of Arg103 with lysine and is significantly altered when a neutral leucine is substituted at this position. A conservative Glu243 to aspartate mutant does not alter either ASA or phosphate binding, but instead results in an eightfold increase in the Km for the coenzyme NADP. Each of the mutations is shown to cause specific subtle active-site structural alterations and each of these changes results in decreases in catalytic efficiency ranging from significant (approximately 3% native activity) to substantial (<0.1% native activity).

The role of substrate-binding groups in the mechanism of aspartate-beta-semialdehyde dehydrogenase.,Blanco J, Moore RA, Faehnle CR, Coe DM, Viola RE Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1388-95. Epub 2004, Jul 21. PMID:15272161[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Moore RA, Bocik WE, Viola RE. Expression and purification of aspartate beta-semialdehyde dehydrogenase from infectious microorganisms. Protein Expr Purif. 2002 Jun;25(1):189-94. PMID:12071715 doi:http://dx.doi.org/10.1006/prep.2002.1626
  2. Blanco J, Moore RA, Faehnle CR, Coe DM, Viola RE. The role of substrate-binding groups in the mechanism of aspartate-beta-semialdehyde dehydrogenase. Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1388-95. Epub 2004, Jul 21. PMID:15272161 doi:10.1107/S0907444904012971

1pu2, resolution 2.06Å

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA