Argininosuccinate lyase

 

Delta crystallin II, the principal crystallin in embryonic lens, is found only in birds and reptiles. This protein also functions (moonlights) as an enzymatically active argininosuccinate lyase (ASL). It catalyses the conversion of L-argininosuccinate to arginine and fumarate.

 

Reference Protein and Structure

Sequence
P24058 UniProt (4.3.2.1) IPR009049 (Sequence Homologues) (PDB Homologues)
Biological species
Anas platyrhynchos (Mallard) Uniprot
PDB
1auw - H91N DELTA 2 CRYSTALLIN FROM DUCK (2.5 Å) PDBe PDBsum 1auw
Catalytic CATH Domains
1.20.200.10 CATHdb (see all for 1auw)
Click To Show Structure

Enzyme Reaction (EC:4.3.2.1)

(N(omega)-L-arginino)succinate(1-)
CHEBI:57472ChEBI
→
L-argininium(1+)
CHEBI:32682ChEBI
+
fumarate(2-)
CHEBI:29806ChEBI
Alternative enzyme names: Arginine-succinate lyase, Argininosuccinic acid lyase, Arginosuccinase, N-(L-argininosuccinate) arginine-lyase, Omega-N-(L-arginino)succinate arginine-lyase, 2-(omega-N-L-arginino)succinate arginine-lyase (fumarate-forming),

Enzyme Mechanism

Introduction

The enzyme catalyses a beta-elimination reaction through a general acid/base mechanism. A histidine residue abstracts a proton from the substrate, forming a carbanion intermediate. Redistribution of negative charge into the carboxyl group generates the aci-carboxylate intermediate. The aci-acid or carbanion intermediates provide the driving force for the expulsion of the fumarate group. The general acid helps the final C-N bond cleavage by donating a proton to the substrate.

Catalytic Residues Roles

UniProt PDB* (1auw)
Lys289 Lys287(289)A Stabilises the negatively charged intermediates. electrostatic stabiliser
Glu296 Glu294(296)A Forms a charge-relay system with the general acid/base histidine. Activating and stabilising the catalytic histidine. activator, proton shuttle (general acid/base)
His162 His160(162)C Acts as a general acid/base. It abstracts a proton from the C-beta atom of the fumarate moiety. The charge-relay interaction of His-160 with Glu-294 adds additional support to this role. proton shuttle (general acid/base)
Ser283 Ser281(283)A General acid/base. proton shuttle (general acid/base)
*PDB label guide - RESx(y)B(C) - RES: Residue Name; x: Residue ID in PDB file; y: Residue ID in PDB sequence if different from PDB file; B: PDB Chain; C: Biological Assembly Chain if different from PDB. If label is "Not Found" it means this residue is not found in the reference PDB.

Chemical Components

References

  1. Wu CY et al. (1998), Biochem J, 333, 327-334. Chemical mechanism of the endogenous argininosuccinate lyase activity of duck lens δ2-crystallin. DOI:10.1042/bj3330327. PMID:9657972.
  2. Sampaleanu LM et al. (2002), J Biol Chem, 277, 4166-4175. Mutational Analysis of Duck  2 Crystallin and the Structure of an Inactive Mutant with Bound Substrate Provide Insight into the Enzymatic Mechanism of Argininosuccinate Lyase. DOI:10.1074/jbc.m107465200. PMID:11698398.
  3. Vallée F et al. (1999), Biochemistry, 38, 2425-2434. Crystal Structure of an Inactive Duck δ II Crystallin Mutant with Bound Argininosuccinate†,‡. DOI:10.1021/bi982149h. PMID:10029536.
  4. Chakraborty AR et al. (1999), Biochemistry, 38, 2435-2443. Mutational Analysis of Amino Acid Residues Involved in Argininosuccinate Lyase Activity in Duck δ II Crystallin†. DOI:10.1021/bi982150g. PMID:10029537.
  5. Abu-Abed M et al. (1997), Biochemistry, 36, 14012-14022. Structural Comparison of the Enzymatically Active and Inactive Forms of δ Crystallin and the Role of Histidine 91†,‡. DOI:10.1021/bi971407s. PMID:9369472.

Step 1.

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Catalytic Residues Roles

Residue Roles
Lys287(289)A electrostatic stabiliser
Ser281(283)A proton shuttle (general acid/base)
Glu294(296)A activator
His160(162)C proton shuttle (general acid/base)
Glu294(296)A proton shuttle (general acid/base)

Chemical Components

Step 1.

Contributors

Stuart Lucas, Craig Porter, Gemma L. Holliday