P-HYDROXYBENZOATE HYDROXYLASE COMPLEXED WITH 4-AMINOBENZOATE AT PH 9.4

pH-dependent structural changes in the active site of p-hydroxybenzoate hydroxylase point to the importance of proton and water movements during catalysis.

Crystal Structures of Wild-Type P-Hydroxybenzoate Hydroxylase Complexed with 4-Aminobenzoate, 2,4-Dihydrobenzoate and 2-Hydroxy-4-Aminobenzoate and of the Tyr222Ala Mutant Complexed with 2-Hydroxy-4-Aminobenzoate.Evidence for a Proton Channel and a New Binding Mode of the Flavin Ring

Crystal Structures of Mutant Pseudomonas Aeruginosa P-Hydroxybenzoate Hydroxylases:The Tyr201Phe, Tyr385Phe and Asn300Asp Variants

Catalytic Function of Tyrosine Residues in Para-Hydroxybenzoate Hydroxylase as Determined by the Study of Site-Directed Mutants

MKTQVAIIGAGPSGLLLGQLLHKAGIDNVILERQTPDYVLGRIRAGVLEQGMVDLLREAGVDRRMARDGLVHEGVEIAFA
GQRRRIDLKRLSGGKTVTVYGQTEVTRDLMEAREACGATTVYQAAEVRLHDLQGERPYVTFERDGERLRLDCDYIAGCDG
FHGISRQSIPAERLKVFERVYPFGWLGLLADTPPVSHELIYANHPRGFALCSQRSATRSRYYVQVPLSEKVEDWSDERFW
TELKARLPSEVAEKLVTGPSLEKSIAPLRSFVVEPMQHGRLFLAGDAAHIVPPTGAKGLNLAASDVSTLYRLLLKAYREG
RGELLERYSAICLRRIWKAERFSWWMTSVLHRFPDTDAFSQRIQQTELEYYLGSEAGLATIAENYVGLPYEEIE

THE HYDROGEN BOND DISTANCE CUTOFF USED FOR THE TURNS IS
3.5 ANGSTROMS. THE CA(X) TO CA(X+4) DISTANCE IS LESS THAN
6.0 ANGSTROMS. THE ANGLES ARE FROM ROBSON AND GARNIER,
(1986), 'INTRODUCTION TO PROTEINS AND PROTEIN ENGINEERING',
ELSEVIER, AMSTERDAM.
TYPE PHI2 PSI2 PHI3 PSI3
I -75(+-65) -30(+-40) -90(+-40) -15 TO 40
II -60(+-40) 120(+-40) 90(+-40) 0(+-40)
III -75(+-65) -30(+-40) -60(+-40) -15 TO -70
I(PRIME) 75(+-65) 30(+-40) 90(+-40) -40 TO 15
II(PRIME) 60(+-40) -120(+-40) -90(+-40) 0(+-40)
III(PRIME) 75(+-65) 30(+-40) 60(+-40) 15 TO 70

MODIFIED CYSTEINE WITH ADDITIONAL ELECTRON DENSITY NEAR
THE SULFUR AT X=5.26, Y=107.89, Z=71.02 - CYS 116. THE
TYPE OF CHEMICAL MODIFICATION CANNOT BE UNAMBIGUOUSLY
DETERMINED FROM THE ELECTRON DENSITY

THE SIDE CHAINS OF RESIDUES 135, 136, 146, 392, 393, 394
ARE NOT ORDERED. THE MODEL IS DERIVED FROM A COMBINATION
OF FIT TO RESIDUAL DENSITY AND ENERGY MINIMIZATION.