Publications

Authors:

Bisello, Giovanni; Ribeiro, Rui Pedro; Perduca, Massimiliano; Belviso, Benny Danilo; Polverino de' Laureto, Patrizia; Giorgetti, Alejandro; Caliandro, Rocco; Bertoldi, Mariarita

Title:

Human aromatic amino acid decarboxylase is an asymmetric and flexible enzyme: implication in AADC deficiency

Year:

2023

Type of item:

Articolo in Rivista

Tipologia ANVUR:

Articolo su rivista

Language:

Inglese

Format:

Elettronico

Referee:

Sì

Name of journal:

Protein Science

ISSN of journal:

0961-8368

N° Volume:

32

Number or Folder:

8

:

Cold Spring Harbor Laboratory Press

Page numbers:

1-16

Keyword:

human aromatic amino acid decarboxylase, AADC deficiency, L-Dopa methylester, molecular dynamics, X-ray diffraction, small angle X-ray scattering

Short description of contents:

Human aromatic amino acid decarboxylase (AADC) is a pyridoxal 5’-phosphate- dependent enzyme responsible for the biosynthesis of dopamine and serotonin, essential neurotransmitters involved in motor and cognitive abilities. Mutations in its gene lead to AADC deficiency, a monogenic rare neurometabolic childhood parkinsonism characterized by severe motor and neurodevelopmental symptoms. Here, for the first time, we solved the crystal structure of human holoAADC in the internal aldimine (1.9Å) and in the external aldimine (2.4Å) of the substrate analog L-Dopa methylester. In this intermediate, the highly flexible AADC catalytic loop is captured in a closed state contacting all protein domains. In addition, each active site, composed by residues of both subunits, is connected to the other through weak interactions and a central cavity. By combining crystallographic analyses with all-atom and coarse-grained molecular dynamics simulations, SAXS investigations and limited proteolysis experiments, we realized that the functionally obligate homodimeric AADC enzyme in solution is an elongated, asymmetric molecule, where the fluctuations of the catalytic loop are coupled to flexibility at the edge between the N-terminal and C-terminal domains. The structural integrity of this peripheral protein region is essential to catalysis, as assessed by both artificial and 37 AADC deficiency pathogenic variants leading to the interpretation that structural dynamics in protein regions far from the active site is essential for catalytic loop flexibility and the acquirement of a correct catalytically competent structure. This could represent the molecular basis for pathogenicity prediction in AADC deficiency.

Web page:

https://onlinelibrary.wiley.com/doi/10.1002/pro.4732

Product ID:

134758

Handle IRIS:

11562/1099930

Last Modified:

August 30, 2023

Bibliographic citation:

Bisello, Giovanni; Ribeiro, Rui Pedro; Perduca, Massimiliano; Belviso, Benny Danilo; Polverino de' Laureto, Patrizia; Giorgetti, Alejandro; Caliandro, Rocco; Bertoldi, Mariarita, Human aromatic amino acid decarboxylase is an asymmetric and flexible enzyme: implication in AADC deficiency «Protein Science» , vol. 32 , n. 8 , 2023 , pp. 1-16

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