ExPASy Proteomics Server

Accession	MF_00465
Dates	18-OCT-2001 (Created) 25-NOV-2009 (Last updated, Version 22)

Data class

Protein

Predictors

HAMAP; MF_00465; [distribution of match scores in UniProtKB];[seed alignment for MF_00465]

Names

AdoMetDC_2

Identifier

SPED

Protein name

RecName: Full=S-adenosylmethionine decarboxylase proenzyme; Short=AdoMetDC; Short=SAMDC; EC=4.1.1.50; RecName: Full=S-adenosylmethionine decarboxylase beta chain; RecName: Full=S-adenosylmethionine decarboxylase alpha chain; Flags: Precursor;

Gene name

speD

FUNCTION: Catalyzes the decarboxylation of S-adenosylmethionine to S-adenosylmethioninamine (dcAdoMet), the propylamine donor required for the synthesis of the polyamines spermine and spermidine from the diamine putrescine (By similarity).

CATALYTIC ACTIVITY: S-adenosyl-L-methionine = (5-deoxy-5-adenosyl)(3-aminopropyl)-methylsulfonium salt + CO(2).

COFACTOR: Pyruvoyl group (By similarity).

PATHWAY: Amine and polyamine biosynthesis; S-adenosylmethioninamine biosynthesis; S-adenosylmethioninamine from S-adenosyl-L-methionine: step 1/1.

SUBUNIT: Heterooctamer of four alpha and four beta chains arranged as a tetramer of alpha/beta heterodimers (By similarity).

PTM: Is synthesized initially as an inactive proenzyme. Formation of the active enzyme involves a self-maturation process in which the active site pyruvoyl group is generated from an internal serine residue via an autocatalytic post-translational modification. Two non-identical subunits are generated from the proenzyme in this reaction, and the pyruvate is formed at the N-terminus of the alpha chain, which is derived from the carboxyl end of the proenzyme. The post-translation cleavage follows an unusual pathway, termed non-hydrolytic serinolysis, in which the side chain hydroxyl group of the serine supplies its oxygen atom to form the C-terminus of the beta chain, while the remainder of the serine residue undergoes an oxidative deamination to produce ammonia and the pyruvoyl group blocking the N-terminus of the alpha chain (By similarity).

SIMILARITY: Belongs to the prokaryotic AdoMetDC family. Type 2 subfamily.

Pfam	PF02675; AdoMet_dc; 1;
TIGRFAMs	TIGR03331; SAM_DCase_Eco; 1;

Autocatalytic cleavage, Decarboxylase, Lyase, Polyamine biosynthesis, Pyruvate, S-adenosyl-L-methionine, Schiff base, Spermidine biosynthesis, Zymogen.

GO:0004014; Molecular function: adenosylmethionine decarboxylase activity.
GO:0006557; Biological process: S-adenosylmethioninamine biosynthetic process.
GO:0006596; Biological process: polyamine biosynthetic process.
GO:0008295; Biological process: spermidine biosynthetic process.

From: SPED_ECOLI (P0A7F6)
Key		From		To		Description		Condition		FTGroup
CHAIN		Nter		111		S-adenosylmethionine decarboxylase beta chain (By similarity)
CHAIN		112		Cter		S-adenosylmethionine decarboxylase alpha chain (By similarity)
ACT_SITE		112		112		Schiff-base intermediate with substrate; via pyruvic acid (By similarity)		S
ACT_SITE		117		117		Proton acceptor; for processing activity (By similarity)		H
ACT_SITE		140		140		Proton donor; for catalytic activity (By similarity)		C
SITE		111		112		Cleavage (non-hydrolytic); by autolysis (By similarity)		K-S
MOD_RES		112		112		Pyruvic acid (Ser); by autocatalysis (By similarity)		S

Size range:	263-290 amino acids
Related UniRules:	None
Template:	P0A7F6 (SPED_ECOLI)
Scope:	Bacteria; Firmicutes Bacteria; Gammaproteobacteria
Fusion:	Nter: None; Cter: None
Duplicate:	None
Plasmid encoded:	None
Comments:	The E.coli protein requires metal cation for activity, and an allosteric mechanism of cation activation has been suggested (PubMed=17567041). This may be the case for all the proteins from the prokaryotic AdoMetDC type 2 subfamily (this rule, MF_00465), but this is not the case for the prokaryotic AdoMetDC type 1 subfamily members (MF_00464).