Sandbox Reserved 1488: Difference between revisions
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== Structure == | == Structure == | ||
The structure of PBP4 was determined to 1.8 Å resolution. Strong electron density was observed for residues 172-680; interpretable electron density was not observed for the N1 domain. The structure show that both PBP4 is composed of three distinct structural domains: N-terminal domain (N2), a non-penicillin binding domain (nPB) and a C-terminal catalytic transpeptidase (TPase) domain, which contains the nucleophilic serine. | The structure of PBP4 was determined to 1.8 Å resolution. Strong electron density was observed for residues 172-680; interpretable electron density was not observed for the N1 domain. The structure show that both PBP4 is composed of three distinct structural domains: N-terminal domain (N2), a non-penicillin binding domain (nPB) and a C-terminal catalytic transpeptidase (TPase) domain, which contains the nucleophilic serine.<scene name='80/802662/Domains_pbp4_e_faecalis/1'>fig.1</scene> | ||
The PBP active site is located in the TPase domain and is defined by three conserved motifs: motif I, which includes the catalytic serine (SxxK: 424STFK427); motif II, which is involved in the protonation of the β-lactam leaving group (S/YxN; 482SDN484); and motif III which facilitates substrate binding and defines the oxyanion hole (K[T/S]GT; 619KTGT622)<ref>DOI: 10.1146/annurev.mi.45.100191.000345</ref>. The nucleophilic serine (Ser424) is located at the N-terminus of helix a2, while the oxyanion hole is defined by the backbone nitrogen atoms of the nucleophilic serine and the motif III threonine (Thr622). These motifs are bordered above by the ‘lid’ (aa 445-473) and below by the C-terminal helix (aa 657-680), which together enclose the active site in a deep cleft. | The PBP active site is located in the TPase domain and is defined by three conserved motifs: motif I, which includes the catalytic serine (SxxK: 424STFK427); motif II, which is involved in the protonation of the β-lactam leaving group (S/YxN; 482SDN484); and motif III which facilitates substrate binding and defines the oxyanion hole (K[T/S]GT; 619KTGT622)<ref>DOI: 10.1146/annurev.mi.45.100191.000345</ref>. The nucleophilic serine (Ser424) is located at the N-terminus of helix a2, while the oxyanion hole is defined by the backbone nitrogen atoms of the nucleophilic serine and the motif III threonine (Thr622). These motifs are bordered above by the ‘lid’ (aa 445-473) and below by the C-terminal helix (aa 657-680), which together enclose the active site in a deep cleft. | ||
