1b5q
A 30 ANGSTROM U-SHAPED CATALYTIC TUNNEL IN THE CRYSTAL STRUCTURE OF POLYAMINE OXIDASE
Structural highlights
FunctionPAO1_MAIZE Flavoenzyme involved in polyamine back-conversion (PubMed:16331971, Ref.4). Catalyzes the oxidation of the secondary amino group of polyamines, such as spermine, spermidine and their acetyl derivatives (PubMed:16331971, Ref.4). Plays an important role in the regulation of polyamine intracellular concentration (Probable).[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: Polyamines are essential for cell growth and differentiation; compounds interfering with their metabolism are potential anticancer agents. Polyamine oxidase (PAO) plays a central role in polyamine homeostasis. The enzyme utilises an FAD cofactor to catalyse the oxidation of the secondary amino groups of spermine and spermidine. RESULTS: The first crystal structure of a polyamine oxidase has been determined to a resolution of 1.9 Angstroms. PAO from Zea mays contains two domains, which define a remarkable 30 Angstrom long U-shaped catalytic tunnel at their interface. The structure of PAO in complex with the inhibitor MDL72527 reveals the residues forming the catalytic machinery and unusual enzyme-inhibitor CH.O H bonds. A ring of glutamate and aspartate residues surrounding one of the two tunnel openings contributes to the steering of the substrate towards the inside of the tunnel. CONCLUSIONS: PAO specifically oxidizes substrates that have both primary and secondary amino groups. The complex with MDL72527 shows that the primary amino groups are essential for the proper alignment of the substrate with respect to the flavin. Conservation of an N-terminal sequence motif indicates that PAO is member of a novel family of flavoenzymes. Among these, monoamine oxidase displays significant sequence homology with PAO, suggesting a similar overall folding topology. A 30-angstrom-long U-shaped catalytic tunnel in the crystal structure of polyamine oxidase.,Binda C, Coda A, Angelini R, Federico R, Ascenzi P, Mattevi A Structure. 1999 Mar 15;7(3):265-76. PMID:10368296[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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