1ehi

[[Image:1ehi.jpg|left|200px]]

|PDB= 1ehi |SIZE=350|CAPTION= <scene name='initialview01'>1ehi</scene>, resolution 2.38&Aring;

|SITE=

|LIGAND= <scene name='pdbligand=ADP:ADENOSINE-5&#39;-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PHY:1(S)-AMINOETHYL-(2-CARBOXYPROPYL)PHOSPHORYL-PHOSPHINIC+ACID'>PHY</scene>

|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/D-alanine--D-alanine_ligase D-alanine--D-alanine ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.2.4 6.3.2.4] </span>

|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ehi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ehi OCA], [http://www.ebi.ac.uk/pdbsum/1ehi PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ehi RCSB]</span>

 

 

 

==Overview==

BACKGROUND: The bacterial cell wall and the enzymes that synthesize it are targets of glycopeptide antibiotics (vancomycins and teicoplanins) and beta-lactams (penicillins and cephalosporins). Biosynthesis of cell wall peptidoglycan requires a crosslinking of peptidyl moieties on adjacent glycan strands. The D-alanine-D-alanine transpeptidase, which catalyzes this crosslinking, is the target of beta-lactam antibiotics. Glycopeptides, in contrast, do not inhibit an enzyme, but bind directly to D-alanine-D-alanine and prevent subsequent crosslinking by the transpeptidase. Clinical resistance to vancomycin in enterococcal pathogens has been traced to altered ligases producing D-alanine-D-lactate rather than D-alanine-D-alanine. RESULTS: The structure of a D-alanine-D-lactate ligase has been determined by multiple anomalous dispersion (MAD) phasing to 2.4 A resolution. Co-crystallization of the Leuconostoc mesenteroides LmDdl2 ligase with ATP and a di-D-methylphosphinate produced ADP and a phosphinophosphate analog of the reaction intermediate of cell wall peptidoglycan biosynthesis. Comparison of this D-alanine-D-lactate ligase with the known structure of DdlB D-alanine-D-alanine ligase, a wild-type enzyme that does not provide vancomycin resistance, reveals alterations in the size and hydrophobicity of the site for D-lactate binding (subsite 2). A decrease was noted in the ability of the ligase to hydrogen bond a substrate molecule entering subsite 2. CONCLUSIONS: Structural differences at subsite 2 of the D-alanine-D-lactate ligase help explain a substrate specificity shift (D-alanine to D-lactate) leading to remodeled cell wall peptidoglycan and vancomycin resistance in Gram-positive pathogens.

 

==About this Structure==

1EHI is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Leuconostoc_mesenteroides Leuconostoc mesenteroides]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EHI OCA].

 

==Reference==

Enzymes of vancomycin resistance: the structure of D-alanine-D-lactate ligase of naturally resistant Leuconostoc mesenteroides., Kuzin AP, Sun T, Jorczak-Baillass J, Healy VL, Walsh CT, Knox JR, Structure. 2000 May 15;8(5):463-70. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10801495 10801495]

[[Category: D-alanine--D-alanine ligase]]

[[Category: Healy, V L.]]

[[Category: Jorczak-Baillass, J.]]

[[Category: Knox, J R.]]

[[Category: Kuzin, A P.]]

[[Category: Sun, T.]]

[[Category: Walsh, C T.]]