Table 1.

Four crystal structures of the S. aureus DNA gyrase GyrBA fusion truncate without inhibitors (apo and binary complexes with DNA)

									Active site 1					Active site 2
No.	PDB code + res.	Inhibitor	Inhibitor pockets occupied						Metal B5081 site occupancies		WHD Tyr C123	DNA	DNA cleavage status	Metal D5081 site occupancies		WHD Tyr A123
			1	1′	2D	2A	3	3′	A	B				A	B
1	2xcqa 2.98	None	–	–	–		–	–	–	–	Tyr	No DNA	N/A	–	–	Tyr
2	2xcoa 3.1	None	–	–	–		–	–	–	–	Tyr	No DNA	N/A	–	–	Tyr
3	6fqv 2.6	None	–	–	–		–	–	–	–	Tyr	20-447 T 20-447 T	Not cleaved	–	–	Tyr
4	5cdr 2.65	None	–	–	–		–	–	–	1.0	Phe	20-12p-8 20-12p-8	Doubly nicked	–	1.0	Phe

This TOPRIM-bound metal is named B5081 (or D5081) to indicate that it is coordinated by Asp 508 from GyrB, in both the A and B positions (see Fig. 6 for details). Active sites are formed across the dimer interface with the catalytic tyrosine from the DC subunit (C123) approaching the B TOPRIM domain, and the tyrosine from the BA subunit (A123) approaching the D subunit TOPRIM domain.

^aGreek key present.