A thermophilic esterase with high activity towards short- to medium-chain p-nitrophenyl carboxylic esters with optimal activity towards the valerate ester. The AF-Est2 has good solvent and pH stability and is very thermostable, showing no loss of activity after incubation for 30min at 80 C. The structure reveals a bound CoA molecule in the vicinity of the active site which regulates substrate specificity
(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Archaea: NE > Euryarchaeota: NE > Archaeoglobi: NE > Archaeoglobales: NE > Archaeoglobaceae: NE > Archaeoglobus: NE > Archaeoglobus fulgidus: NE
Warning: This entry is a compilation of different species or line or strain with more than 90% amino acid identity. You can retrieve all strain data
(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) Archaeoglobus fulgidus DSM 8774: N, E.
Archaeoglobus fulgidus DSM 4304: N, E.
Molecular evidence
Database
No mutation 1 structure: 5FRD: Structure of a thermophilic esterase No kinetic
MLERVFIDVDGVKVSLLKGRERKVFYIHSSGSDATQWVNQLTAIGGYAID
LPNHGQSDTVEVNSVDEYAYYASESLKKTVGKAVVVGHSLGGAVAQKLYL
RNPEICLALVLVGTGARLRVLPEILEGLKKEPEKAVDLMLSMAFASKGEE
YEKKRREFLDRVDVLHLDLSLCDRFDLLEDYRNGKLKIGVPTLVIVGEED
KLTPLKYHEFFHKHIPNSELVVIPGASHMVMLEKHVEFNEALEKFLKKVG
V
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MLERVFIDVDGVKVSLLKGRERKVFYIHSSGSDATQWVNQLTAIGGYAID LPNHGQSDTVEVNSVDEYAYYASESLKKTVGKAVVVGHSLGGAVAQKLYL RNPEICLALVLVGTGARLRVLPEILEGLKKEPEKAVDLMLSMAFASKGEE YEKKRREFLDRVDVLHLDLSLCDRFDLLEDYRNGKLKIGVPTLVIVGEED KLTPLKYHEFFHKHIPNSELVVIPGASHMVMLEKHVEFNEALEKFLKKVG V
A new carboxyl esterase, AF-Est2, from the hyperthermophilic archaeon Archaeoglobus fulgidus has been cloned, over-expressed in Escherichia coli and biochemically and structurally characterized. The enzyme has high activity towards short- to medium-chain p-nitrophenyl carboxylic esters with optimal activity towards the valerate ester. The AF-Est2 has good solvent and pH stability and is very thermostable, showing no loss of activity after incubation for 30 min at 80 degrees C. The 1.4 A resolution crystal structure of AF-Est2 reveals Coenzyme A (CoA) bound in the vicinity of the active site. Despite the presence of CoA bound to the AF-Est2 this enzyme has no CoA thioesterase activity. The pantetheine group of CoA partially obstructs the active site alcohol pocket suggesting that this ligand has a role in regulation of the enzyme activity. A comparison with closely related alpha/beta hydrolase fold enzyme structures shows that the AF-Est2 has unique structural features that allow CoA binding. A comparison of the structure of AF-Est2 with the human carboxyl esterase 1, which has CoA thioesterase activity, reveals that CoA is bound to different parts of the core domain in these two enzymes and approaches the active site from opposite directions.
Archaeoglobus fulgidus is the first sulphur-metabolizing organism to have its genome sequence determined. Its genome of 2,178,400 base pairs contains 2,436 open reading frames (ORFs). The information processing systems and the biosynthetic pathways for essential components (nucleotides, amino acids and cofactors) have extensive correlation with their counterparts in the archaeon Methanococcus jannaschii. The genomes of these two Archaea indicate dramatic differences in the way these organisms sense their environment, perform regulatory and transport functions, and gain energy. In contrast to M. jannaschii, A. fulgidus has fewer restriction-modification systems, and none of its genes appears to contain inteins. A quarter (651 ORFs) of the A. fulgidus genome encodes functionally uncharacterized yet conserved proteins, two-thirds of which are shared with M. jannaschii (428 ORFs). Another quarter of the genome encodes new proteins indicating substantial archaeal gene diversity.
Archaeoglobus fulgidus thermophilic esterase AF1537
