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Wayne Decatur, Student, Allison Granberry

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	==='''Structure of PBP2a, a B-Lactam Resistant Transpeptidase'''===		==='''Structure of PBP2a, a B-Lactam Resistant Transpeptidase'''===
	Isolates of methicillin-resistant S. aureus (MRSA) are resistant to almost all currently available B-lactams because they have acquired an alternative PBP, PBP2A (encoded by the mecA gene) that is neither bound nor inhibited by B-lactams. PBP2a is composed of two domains: <font color='orangered'><b>a non-penicillin binding domain </b><scene name='37/372728/Npb_domain/1'>(NPB)</scene></font> and a <font color='~~black~~'>transpeptidase<scene name='37/372728/Tp_domain/1'>TP</scene>-binding domain. The NBP domain of PBP2a is anchored in the cell membrane, while the TP domain residues in the periplasm with its active site facing the inner surface of the cell wall. The active site contains <scene name='37/372724/Serine403label/2'> a serine residue at position 403 (Ser403)</scene>, which catalyzes the cross-linking of the peptidoglycan rows with pentaglycine cross-links.		Isolates of methicillin-resistant S. aureus (MRSA) are resistant to almost all currently available B-lactams because they have acquired an alternative PBP, PBP2A (encoded by the mecA gene) that is neither bound nor inhibited by B-lactams. PBP2a is composed of two domains: <font color='orangered'><b>a non-penicillin binding domain </b><scene name='37/372728/Npb_domain/1'>(NPB)</scene></font> and a <font color='dodgerblue'>transpeptidase<scene name='37/372728/Tp_domain/1'>TP</scene>-binding domain </b></font>. The NBP domain of PBP2a is anchored in the cell membrane, while the TP domain residues in the periplasm with its active site facing the inner surface of the cell wall. The active site contains <scene name='37/372724/Serine403label/2'> a serine residue at position 403 (Ser403)</scene>, which catalyzes the cross-linking of the peptidoglycan rows with pentaglycine cross-links.