Untitled

Suresh, C.G.; Pundle, Archana; SivaRaman, H.; Rao, K.N.; Brannigan, J.A.; McVey, Colin E.; Verma, Chandra; Dauter, Zbigniew; Dodson, E.J.; Dodson, Guy

doi:10.1038/8213

Cited by 105 publications

(41 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The human gene was reported to be located in the region of 4q21.1 (46). We found that NAAA belongs to the choloylglycine hydrolase family (Pfam PF02275), which includes AC, choloylglycine hydrolase (conjugated bile acid hydrolase), and penicillin V acylase (55,56). These enzymes cleave carbon-nitrogen bonds, other than peptide bonds, in linear amides.…”

Section: Discussionmentioning

confidence: 99%

Molecular Characterization of N-Acylethanolamine-hydrolyzing Acid Amidase, a Novel Member of the Choloylglycine Hydrolase Family with Structural and Functional Similarity to Acid Ceramidase

Tsuboi

Sun

Okamoto

et al. 2005

Journal of Biological Chemistry

297

287

View full text Add to dashboard Cite

Bioactive N-acylethanolamines, including anandamide (an endocannabinoid) and N-palmitoylethanolamine (an anti-inflammatory and neuroprotective substance), are hydrolyzed to fatty acids and ethanolamine by fatty acid amide hydrolase. Moreover, we found another amidohydrolase catalyzing the same reaction only at acidic pH, and we purified it from rat lung (Ueda, N., Yamanaka, K., and Yamamoto, S. (2001) J. Biol. Chem. 276, 35552-35557). Here we report complementary DNA cloning and functional expression of the enzyme termed "N-acylethanolamine-hydrolyzing acid amidase (NAAA)" from human, rat, and mouse. The deduced primary structures revealed that NAAA had no homology to fatty acid amide hydrolase but belonged to the choloylglycine hydrolase family. Human NAAA was essentially identical to a gene product that had been noted to resemble acid ceramidase but lacked ceramide hydrolyzing activity. The recombinant human NAAA overexpressed in HEK293 cells hydrolyzed various N-acylethanolamines with N-palmitoylethanolamine as the most reactive substrate. Most interestingly, a very low ceramide hydrolyzing activity was also detected with NAAA, and N-lauroylethanolamine hydrolyzing activity was observed with acid ceramidase. By the use of tunicamycin and endoglycosidase, NAAA was found to be a glycoprotein. Furthermore, the enzyme was proteolytically processed to a shorter form at pH 4.5 but not at pH 7.4. Expression analysis of a green fluorescent protein-NAAA fusion protein showed a lysosome-like distribution in HEK293 cells. The organ distribution of the messenger RNA in rats revealed its wide distribution with the highest expression in lung. These results demonstrated that NAAA is a novel N-acylethanolamine-hydrolyzing enzyme that shows structural and functional similarity to acid ceramidase.

show abstract

Section: Discussionmentioning

confidence: 99%

Molecular Characterization of N-Acylethanolamine-hydrolyzing Acid Amidase, a Novel Member of the Choloylglycine Hydrolase Family with Structural and Functional Similarity to Acid Ceramidase

Tsuboi

Sun

Okamoto

et al. 2005

Journal of Biological Chemistry

297

287

View full text Add to dashboard Cite

show abstract

“…In addition, the site displays better dyad symmetry than the one at tcpPH, suggesting that AphA might bind to it with even higher affinity. The cholylglycine family of hydrolases comprise both conjugated bile salt hydrolases and PVAs, since they share extensive sequence homology (5) and belong to the same group of Nterminal nucleophile hydrolases in which Cys-1 plays an essential role in the catalytic mechanism of the enzyme (42). VCA0877 is predicted to encode a 38-kDa protein with approximately 26% identity to the conjugated bile salt hydrolase from Clostridium perfringens (6) and 25% identity to PVA from Bacillus sphaericus (37).…”

Section: Resultsmentioning

confidence: 99%

“…These amidases have distinct substrate preferences, with PVA being active on phenoxyacetylated derivatives, such as penicillin V, and penicillin G amidase (PGA) being active on phenylacetylated derivatives, such as penicillin G. Although the two enzymes have no detectable sequence homology, common structural patterns have been identified between them by X-ray crystallography (42). PVA from B. sphaericus is a tetrameric enzyme consisting of four identical subunits with a monomer molecular size of 35 kDa (36).…”

Section: Discussionmentioning

confidence: 99%

The Virulence Activator AphA Links Quorum Sensing to Pathogenesis and Physiology in Vibrio cholerae by Repressing the Expression of a Penicillin Amidase Gene on the Small Chromosome

2003

View full text Add to dashboard Cite

Activation of the tcpPH promoter on the Vibrio pathogenicity island by AphA and AphB initiates the Vibrio cholerae virulence cascade and is regulated by quorum sensing through the repressive action of HapR on aphA expression. To further understand how the chromosomally encoded AphA protein activates tcpPH expression, site-directed mutagenesis was used to identify the base pairs critical for AphA binding and transcriptional activation. This analysis revealed a region of partial dyad symmetry, TATGCA-N6-TNCNNA, that is important for both of these activities. Searching the V. cholerae genome for this binding site permitted the identification of a second one upstream of a penicillin V amidase (PVA) gene on the small chromosome. AphA binds to and footprints this site, which overlaps the pva transcriptional start, consistent with its role as a repressor at this promoter. Since aphA expression is under quorum-sensing control, the response regulators LuxO and HapR also influence pva expression. Thus, pva is repressed at low cell density when AphA levels are high, and it is derepressed at high cell density when AphA levels are reduced. Penicillin amidases are thought to function as scavengers for phenylacetylated compounds in the nonparasitic environment. That AphA oppositely regulates the expression of pva from that of virulence, together with the observation that PVA does not play a role in virulence, suggests that these activities are coordinated to serve V. cholerae in different biological niches.

show abstract

“…The N-terminal residue of subunit ␤, a threonine, serine, or cysteine, acts as the active nucleophile in the catalytic mechanism. The crystal structures reported for several members of this family, including ornithine acetyltransferase (16), human (17), and Flavobacterium meningosepticum aspartylglucosaminidases (18,19), the proteasome ␤-subunit (20), glutamine 5-phosphoribosyl-1-pyrophosphate amidotransferase (21), acylases of penicillin G (22) and penicillin V (23), as well as cephalosporin acylases (24,25), have revealed that, although the amino acid sequences of these proteins vary considerably, they all have the same fold. The polypeptide chains of these proteins are organized into a sandwich of two extended parallel ␤-sheets, flanked on both sides by ␣-helices.…”

mentioning

confidence: 99%

Crystal Structure of Isoaspartyl Aminopeptidase in Complex with l-Aspartate

Michalska

Brzeziński

Jaskólski

2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

The crystal structure of Escherichia coli isoaspartyl aminopeptidase/asparaginase (EcAIII), an enzyme belonging to the N-terminal nucleophile (Ntn)-hydrolases family, has been determined at 1.9-Å resolution for a complex obtained by cocrystallization with L-aspartate, which is a product of both enzymatic reactions catalyzed by EcAIII. The enzyme is a dimer of heterodimers, (␣␤) 2 . The (␣␤) heterodimer, which arises by autoproteolytic cleavage of the immature protein, exhibits an ␣␤␤␣-sandwich fold, typical for Ntn-hydrolases. The asymmetric unit contains one copy of the EcAIII⅐Asp complex, with clearly visible L-aspartate ligands, one bound in each of the two active sites of the enzyme. The L-aspartate ligand is located near Thr 179 , the N-terminal residue of subunit ␤ liberated in the autoproteolytic event. Structural comparisons with the free form of EcAIII reveal that there are no major rearrangements of the active site upon aspartate binding. Although the ligand binding mode is similar to that observed in an L-aspartate complex of the related enzyme human aspartylglucosaminidase, the architecture of the EcAIII active site sheds light on the question of substrate specificity and explains why EcAIII is not able to hydrolyze glycosylated asparagine substrates.Proteins undergo several age-dependent spontaneous modifications that can limit their useful lifetime. In particular, deamidated, racemized, or isomerized derivatives can be formed in an intramolecular succinimide-mediated rearrangement involving L-asparaginyl or, in a 13-36-fold slower reaction (1), L-aspartyl residues (2). The major product is an Lisoaspartyl (iAsp) 1 -containing protein, in which the peptide backbone has been transferred to the side chain forming a ␤-peptide. Such a serious structural rearrangement usually leads to protein dysfunction. Two mechanisms have been proposed by which organisms may handle the useless proteins and prevent accumulation of the harmful iAsp (3-5).One well defined mechanism involves the repair of some products of spontaneous damage to intracellular proteins. It is based on the enzyme L-isoaspartyl(D-aspartyl)-O-methyltransferase (O-MT), which is found in organisms ranging from bacteria to mammals and plants and initiates the repair pathway by methylation of L-isoaspartyl residues (and D-aspartyl residues in racemized derivatives) (6, 7). Despite the quite wide range of recognized substrates, the repair activity of O-MT is limited (8, 9). The damaged proteins that are not identified and repaired by the enzyme are degraded by cellular proteases to free amino acids and to the relatively stable iAsp-containing diand tripeptides. To prevent accumulation of those harmful isoaspartyl peptides, specialized enzymes with peptidase activity are required (10). Enzymes with isoaspartyl peptidase activity (EC 3.4.19.5) were initially isolated from mammals (10) and bacteria (11). Further studies have revealed the existence of two classes of isoaspartyl peptidases. The first class includes metallopeptidases represented by the Es...

show abstract

Untitled

Cited by 105 publications

References 23 publications

Molecular Characterization of N-Acylethanolamine-hydrolyzing Acid Amidase, a Novel Member of the Choloylglycine Hydrolase Family with Structural and Functional Similarity to Acid Ceramidase

Molecular Characterization of N-Acylethanolamine-hydrolyzing Acid Amidase, a Novel Member of the Choloylglycine Hydrolase Family with Structural and Functional Similarity to Acid Ceramidase

The Virulence Activator AphA Links Quorum Sensing to Pathogenesis and Physiology in Vibrio cholerae by Repressing the Expression of a Penicillin Amidase Gene on the Small Chromosome

Crystal Structure of Isoaspartyl Aminopeptidase in Complex with l-Aspartate

Contact Info

Product

Resources

About