This
is an enlargement of the active site for the D-alanyl-D-alanine Carboxypeptidase.
The Cefotaxime molecule is a Penicillin analog (similar in structure to
Penicillin), therefore it binds in the same site that Penicillin does.
[In all of the protein databases that we searched we could not find any
protein crystal structures which were actually bound to a Penicillin.]
The residues are colored in the same way as the full molecule (previous
page): N-terminal end = more blue, C-terminal end = more green. This is
also indicated by the numbers. Most of the residues in this binding site
are polar (Aparagine, Tyrosine, Threonine, Glutamine, and Histidine), which
is appropriate considering that the enzyme binds to a charged bipeptide
(D-alanyl-D-alanine).