Protein and nucleotide deglycase that catalyzes the deglycation of the Maillard adducts formed between amino groups of proteins or nucleotides and reactive carbonyl groups of glyoxals (PubMed:26102038, PubMed:26774339, PubMed:28596309). Thus, functions as a protein deglycase that repairs methylglyoxal- and glyoxal-glycated proteins, and releases repaired proteins and lactate or glycolate, respectively. Deglycates cysteine, arginine and lysine residues in proteins, and thus reactivates these proteins by reversing glycation by glyoxals. Is able to repair glycated serum albumin, aspartate aminotransferase, glyceraldehyde-3-phosphate dehydrogenase, and fructose biphosphate aldolase. Acts on early glycation intermediates (hemithioacetals and aminocarbinols), preventing the formation of Schiff bases and advanced glycation endproducts (AGE) that cause irreversible damage (PubMed:26102038, PubMed:26774339). Also functions as a nucleotide deglycase able to repair glycated guanine in the free nucleotide pool (GTP, GDP, GMP, dGTP) and in DNA and RNA. Is thus involved in a major nucleotide repair system named guanine glycation repair (GG repair), dedicated to reversing methylglyoxal and glyoxal damage via nucleotide sanitization and direct nucleic acid repair (PubMed:28596309). Has been reported to display chaperone, peptidase and glutathione-independent glyoxalase activities (PubMed:12235139, PubMed:12565879, PubMed:14731284, PubMed:15550391, PubMed:7848303, PubMed:21696459). However, these apparently disparate activities are all recruited to execute its protein deglycase primary function (PubMed:26102038, PubMed:26774339). Plays an important role in protecting cells from carbonyl stress, severe heat shock and starvation, as well as in acid resistance of stationary-phase cells (PubMed:12235139, PubMed:16796689, PubMed:17158627). H2O + methylglyoxal = (R)-lactate + H(+) H2O + N(omega)-(1-hydroxy-2-oxopropyl)-L-arginyl-[protein] = H(+) + L-arginyl-[protein] + lactate H2O + N(6)-(1-hydroxy-2-oxopropyl)-L-lysyl-[protein] = H(+) + L-lysyl-[protein] + lactate H2O + S-(1-hydroxy-2-oxopropyl)-L-cysteinyl-[protein] = H(+) + L-cysteinyl-[protein] + lactate H2O + N(omega)-(1-hydroxy-2-oxoethyl)-L-arginyl-[protein] = glycolate + H(+) + L-arginyl-[protein] H2O + N(6)-(1-hydroxy-2-oxoethyl)-L-lysyl-[protein] = glycolate + H(+) + L-lysyl-[protein] H2O + S-(1-hydroxy-2-oxoethyl)-L-cysteinyl-[protein] = glycolate + H(+) + L-cysteinyl-[protein] H2O + N(2)-(1-hydroxy-2-oxopropyl)-dGTP = dGTP + H(+) + lactate H2O + N(2)-(1-hydroxy-2-oxopropyl)-GTP = GTP + H(+) + lactate H2O + N(2)-(1-hydroxy-2-oxopropyl)-GDP = GDP + H(+) + lactate H2O + N(2)-(1-hydroxy-2-oxopropyl)-GMP = GMP + H(+) + lactate H2O + N(2)-(1-hydroxy-2-oxoethyl)-dGTP = dGTP + glycolate + H(+) H2O + N(2)-(1-hydroxy-2-oxoethyl)-GTP = glycolate + GTP + H(+) H2O + N(2)-(1-hydroxy-2-oxoethyl)-GDP = GDP + glycolate + H(+) H2O + N(2)-(1-hydroxy-2-oxoethyl)-GMP = glycolate + GMP + H(+) an N(2)-(1-hydroxy-2-oxopropyl)-guanosine in RNA + H2O = a guanosine in RNA + H(+) + lactate an N(2)-(1-hydroxy-2-oxopropyl)-2'-deoxyguanosine in DNA + H2O = a 2'-deoxyguanosine in DNA + H(+) + lactate an N(2)-(1-hydroxy-2-oxoethyl)-guanosine in RNA + H2O = a guanosine in RNA + glycolate + H(+) an N(2)-(1-hydroxy-2-oxoethyl)-2'-deoxyguanosine in DNA + H2O = a 2'-deoxyguanosine in DNA + glycolate + H(+) The glyoxalase activity is inhibited by copper and zinc cations, activated by ferrous cations, and inactivated by thiol-blocking reagents (PubMed:21696459, PubMed:7848303). The aminopeptidase activity is inhibited by iodoacetamide, dithiothreitol, EDTA and 1, 10-phenanthroline (PubMed:15550391). Binding of ATP at high temperatures induces a conformational change that reduces HchA surface hydrophobicity, interferes with its ability to capture substrate proteins and inhibits chaperone activity (PubMed:12235139). kcat is 156.9 min(-1) for glyoxalase activity with methylglyoxal as substrate (PubMed:21696459). kcat is 0.43 min(-1) for aminopeptidase activity with Lys-AMC as substrate. kcat is 0.51 min(-1) for aminopeptidase activity with Arg-AMC as substrate. kcat is 1.1 min(-1) for aminopeptidase activity with Ala-AMC as substrate (PubMed:15550391). Optimum pH is between 6 and 8 for glyoxalase activity (PubMed:21696459, PubMed:7848303). Significant inhibition of glyoxalase activity below pH 5 (PubMed:21696459). Optimum pH is 8 for aminopeptidase activity (PubMed:15550391). Optimum temperature for glyoxalase activity is around 37 degrees Celsius (PubMed:21696459). Optimum temperature for aminopeptidase activity is around 43 degrees Celsius (PubMed:15550391). Homodimer. By heat shock. Consists of a large A domain and a smaller P domain connected by a linker. The thermally induced motion of the flexible linker-loop region leads to the uncovering of a high-affinity substrate-binding site that is essential to capture nonnative proteins at high temperatures. Cells lacking this gene show a loss of glyoxalase and reduction in aminopeptidase activity (PubMed:15550391, PubMed:21696459). They accumulate methylglyoxal and are more susceptible to methylglyoxal than the parent strain (PubMed:21696459). Cells exhibit growth defects above 48 degrees Celsius and accumulate higher levels of peptides than wild-type (PubMed:14731284, PubMed:15550391). They display increased protein and DNA/RNA glycation levels, and exhibit strong mutator phenotypes (PubMed:26102038, PubMed:28596309). Moreover, the double and triple mutants lacking yhbO and yajL, and yhbO, yajL and hchA, respectively, display impressive amounts of glycated proteins, suggesting that the YhbO, YajL and Hsp31 deglycases display relatively redundant functions (PubMed:26774339). The triple mutant displays higher glycation levels of free nucleotides (GTP and dGTP) than the parental strain, and shows higher glycation levels of DNA and RNA than those of single mutants (PubMed:28596309). The hchA mutant cells show decreased viability in methylglyoxal- or glucose-containing media (PubMed:26774339). According to some authors, HchA exhibits an exceedingly weak proteolytic activity against bovine serum albumin (BSA) and some peptidase activity against small single amino acids conjugated to a fluorogenic reporter (PubMed:12939276). Another report showed that HchA does not display any significant proteolytic activity but displays a physiologically relevant aminopeptidase activity (PubMed:15550391). Belongs to the peptidase C56 family. HchA subfamily. The protein deglycation activity has been ascribed to a TRIS buffer artifact by a publication (PubMed:27903648), which has then been rebutted by clear biochemical experiments showing that DJ-1 family deglycases are bona fide deglycases (PubMed:28013050). Deglycase activity is even strengthened by a novel article that reports nucleotide deglycation activity (PubMed:28596309).