>cd04931 ACT_PAH ACT domain of the nonheme iron-dependent aromatic amino acid hydroxylase, phenylalanine hydroxylases (PAH). ACT domain of the nonheme iron-dependent aromatic amino acid hydroxylase, phenylalanine hydroxylases (PAH). PAH catalyzes the hydroxylation of L-Phe to L-Tyr, the first step in the catabolic degradation of L-Phe. In PAH, an autoregulatory sequence, N-terminal of the ACT domain, extends across the catalytic domain active site and regulates the enzyme by intrasteric regulation. It appears that the activation by L-Phe induces a conformational change that converts the enzyme to a high-affinity and high-activity state. Modulation of activity is achieved through inhibition by BH4 and activation by phosphorylation of serine residues of the autoregulatory region. The molecular basis for the cooperative activation process is not fully understood yet. Members of this CD belong to the superfamily of ACT regulatory domains.

Probab=96.92  E-value=0.0077  Score=39.97  Aligned_cols=67  Identities=16%  Similarity=0.263  Sum_probs=51.5

Q ss_pred             EEEEEEECCCCCHHHHHHHHHHHCCCCEEEEEECCCCCCCCEEEEEEEEEECCHHHHHHHHHHHHCC
Q ss_conf             2799992488874899999988669957888822677877613599992104889999999986238
Q gi|254780900|r  354 YFIRLTIRNFEGILDKITSQMSDFNISLRLFSCPHQEENSQEFSVFMITHKVSGKLIRDAIECFNGK  420 (438)
Q Consensus       354 yYLRl~v~DkpGVLa~It~ilak~~ISIesi~Q~~~~~~~~~~~IViiTh~~~e~~i~~ai~~i~~l  420 (438)
T Consensus        15 tSlifs~~~~~GaL~~~L~~F~~~~INLt~IESRPsk~~~~eY~FfVD~e~~~~~~l~~~i~~Lr~~   81 (90)
T cd04931          15 ISLIFSLKEEVGALAKVLRLFEEKDINLTHIESRPSRLNKDEYEFFINLDKKSAPALDPIIKSLRND   81 (90)
T ss_pred             EEEEEEECCCCCHHHHHHHHHHHCCCCEEEEECCCCCCCCCEEEEEEEECCCCCHHHHHHHHHHHHH
T ss_conf             8999993897677999999999879674788767489999608999992388757799999999985