(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > PVC group: NE > Planctomycetes: NE > Planctomycetia: NE > Planctomycetales: NE > Planctomycetaceae: NE > Thermogutta: NE > Thermogutta terrifontis: NE
BD-FAE : 9bact-TtEst2 Thermogutta terrifontis thermophilic esterase with minimal cap domain from a Planctomycetes species
Molecular evidence
Database
No mutation 5 structures(e.g. : 4UHC, 4UHD, 4UHE... more)(less) 4UHC: Structural studies of a thermophilic esterase from Thermogutta terrifontis (Native), 4UHD: Structural studies of a thermophilic esterase from Thermogutta terrifontis (acetate bound), 4UHE: Structural studies of a thermophilic esterase from Thermogutta terrifontis (malate bound), 4UHF: Structural studies of a thermophilic esterase from Thermogutta terrifontis (L37A mutant with butyrate bound), 4UHH: Structural studies of a thermophilic esterase from Thermogutta terrifontis (cacodylate complex) No kinetic
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 MAQRVKITTTATPGEIELAFEDTGTGLPVLLVHGFPLDRTMWKAQREELC DEFRVIVPDLRGFGESQVIPGVATMEAMADDLAGLCNHLGLTGKIVLGGL SMGGYVAFAFARKYRDRLAGLILCDTRARPDSPEAKENRRRVAERVRREG PGFIAEEMIPRLCCESTFRNHPEVIEKIRQMILSAPPEGVAAAALGMAER PDSTDLLPALSCPTLVLVGQFDAISPPEEMEAMARTIPQSQFVVIPDAGH LPPMEQPERVTQAIREWLRKVHTEAG
Monoacylglycerol lipases (MGL) are a subclass of lipases that predominantly hydrolyze monoacylglycerol (MG) into glycerol and fatty acid. MGLs are ubiquitous enzymes across species and play a role in lipid metabolism, affecting energy homeostasis and signaling processes. Structurally, MGLs belong to the alpha/beta hydrolase fold family with a cap covering the substrate binding pocket. Analysis of the known 3D structures of human, yeast and bacterial MGLs revealed striking similarity of the cap architecture. Since MGLs from different organisms share very low sequence similarity, it is difficult to identify MGLs based on the amino acid sequence alone. Here, we investigated whether the cap architecture could be a characteristic feature of this subclass of lipases with activity towards MG and whether it is possible to identify MGLs based on the cap shape. Through database searches, we identified the structures of five different candidate alpha/beta hydrolase fold proteins with unknown or reported esterase activity. These proteins exhibit cap architecture similarities to known human, yeast and bacterial MGL structures. Out of these candidates we confirmed MGL activity for the protein LipS, which displayed the highest structural similarity to known MGLs. Two further enzymes, Avi_0199 and VC1974, displayed low level MGL activities. These findings corroborate our hypothesis that this conserved cap architecture can be used as criterion to identify lipases with activity towards MGs.
Thermogutta terrifontis esterase (TtEst), a carboxyl esterase identified in the novel thermophilic bacterium T. terrifontis from the phylum Planctomycetes, has been cloned and over-expressed in Escherichia coli. The enzyme has been characterized biochemically and shown to have activity towards small p-nitrophenyl (pNP) carboxylic esters, with optimal activity for pNP-propionate. The enzyme retained 95% activity after incubation for 1 h at 80 degrees C. The crystal structures of the native TtEst and its complexes with the substrate analogue d-malate and the product acetate have been determined to high resolution. The bound ligands have allowed the identification of the carboxyl and alcohol binding pockets in the enzyme active site. Comparison of TtEst with structurally related enzymes provides insight into how differences in their catalytic activity can be rationalized based upon the properties of the amino acid residues in their active site pockets. The mutant enzymes L37A and L251A have been constructed to extend the substrate range of TtEst towards the larger butyrate and valerate pNP-esters. These mutant enzymes have also shown a significant increase in activity towards acetate and propionate pNP esters. A crystal structure of the L37A mutant was determined with the butyrate product bound in the carboxyl pocket of the active site. The mutant structure shows an expansion of the pocket that binds the substrate carboxyl group, which is consistent with the observed increase in activity towards pNP-butyrate. DATABASE: The GenBank sequence accession number for the Thermogutta terrifontis esterase is KR002593. The protein structures for T. terrifontis esterase and their complexes have been deposited in the Protein Data Bank with codes: 4UHC (native), 4UHD (acetate bound), 4UHE (malate bound) and 4UHF (L37A mutant with butyrate bound).
Thermogutta terrifontis thermophilic esterase from a new Planctomycetes species
