Crystal structure of PBP1a in complex with compound 17 ((4Z,8S,11E,14S)-5-(2-amino-1,3-thiazol-4-yl)-14-(5,6-dihydroxy-1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-8-formyl-2-methyl-6-oxo-3,10-dioxa-4,7,11-triazatetradeca-4,11-diene-2,12,14-tricarboxylic acid)