(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > Proteobacteria: NE > Betaproteobacteria: NE > Burkholderiales: NE > Alcaligenaceae: NE > Alcaligenes: NE > Alcaligenes faecalis: 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.) Alcaligenes faecalis subsp. faecalis NCIB 8687: N, E.
Alcaligenes faecalis subsp. faecalis NBRC 13111: N, E.
Alcanivorax sp. 24: N, E.
Alcanivorax sp. 6-D-6: N, E.
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 MTSRPMRSLVIAFLTLVAAAAPALAGAGAWQNNLSLGGFNKVHLYTPDGD SPVGNGKALLIVLHGCTQSIDAYKTANLEVAAEEYGMVVAVPDAMNKAGF SCWSYWQGTKSRSAGDYKNLINLANTLSGDAARGIDPNQVYIAGLSSGAS FANTTACLAPDVFAGVGVSAGPSVGTSSSGAIGTCEQADVESRCRDLGGG YQSAFDTQVASIAHGDADTTVDTCYNRQNAEGMAGLYGVSEVAGSTVINA DGGSAEEFLWQDGRVSMLWFHGLDHSWSGGQGASGSYVSGASINYARYLG GFFAEHNAR
Pristine marine environments are highly oligotrophic ecosystems populated by well-established specialised microbial communities. Nevertheless, during oil spills, low-abundant hydrocarbonoclastic bacteria bloom and rapidly prevail over the marine microbiota. The genus Alcanivorax is one of the most abundant and well-studied organisms for oil degradation. While highly successful under polluted conditions due to its specialised oil-degrading metabolism, it is unknown how they persist in these environments during pristine conditions. Here we show that part of the Alcanivorax genus, as well as oils, has an enormous potential for biodegrading aliphatic polyesters thanks to a unique and abundantly secreted alpha/beta hydrolase. The heterologous overexpression of this esterase proved a remarkable ability to hydrolyse both natural and synthetic polyesters. Our findings contribute to i) better understand the ecology of Alcanivorax in its natural environment, where natural polyesters such as polyhydroxyalkanoates (PHA) are produced by a large fraction of the community and, hence, an accessible source of carbon and energy used by the organism in order to persist, ii) highlight the potential of Alcanivorax to clear marine environments from polyester materials of anthropogenic origin as well as oils, and iii) the discovery of a new versatile esterase with a high biotechnological potential. This article is protected by copyright. All rights reserved.
Title: Substrate and binding specificities of bacterial polyhydroxybutyrate depolymerases Kasuya K, Ohura T, Masuda K, Doi Y Ref: Int J Biol Macromol, 24:329, 1999 : PubMed
The substrate specificities of three extracellular polyhydroxybutyrate (PHB) depolymerases from Alcaligenes faecalis (PhaZ Afa), Pseudomonas stutzeri (PhaZ Pst), and Comamonas acidovorans (PhaZ Cac), which are grouped into types A and B based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. Each of these PHB depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (P(3HB)), poly(3-hydroxypropionate) (P(3HP)), poly(4-hydroxybutyrate) (P(4HB)), poly(ethylene succinate) (PESU), and poly(ethylene adipate) (PEA) but could not hydrolyze another seven polyesters. In addition, the binding characteristics of substrate binding domains from PhaZ Afa, PhaZ Cac, and PHB depolymerase from Comamonas testosteroni (PhaZ Cte) were studied by using fusions with glutathione S-transferase (GST). All of fusion proteins adsorbed strongly on the surfaces of polyester granules of P(3HB), P(3HP), and poly(2-hydroxypropionate) (P(2HP)) which was not hydrolyzed by the PHB depolymerases used in this study, while they did not bind on Avicel and chitin granules. The adsorption kinetics of the fusion proteins to the surface of P(3HB) and P(2HP) granules were found to obey the Langmuir isotherm. The cross-area per molecule of fusion protein bound to P(3HB) granules was estimated to be 12+/-4 nm2/molecule. It has been suggested that the active sites in catalytic domains of PHB depolymerases have a similar conformational structure, and that several amino acids in substrate-binding domains of PHB depolymerases interact specifically with the surface of polyesters.
Title: Cloning of poly(3-hydroxybutyrate) depolymerase from a marine bacterium, Alcaligenes faecalis AE122, and characterization of its gene product Kita K, Mashiba S, Nagita M, Ishimaru K, Okamoto K, Yanase H, Kato N Ref: Biochimica & Biophysica Acta, 1352:113, 1997 : PubMed
A DNA fragment that carries the gene coding for poly(3-hydroxybutyrate) (PHB) depolymerase was cloned from the chromosomal DNA of Alcaligenes faecalis AE122 isolated from seawater. The open reading frame encoding the precursor of the PHB depolymerase was 1905 base pairs (bp) long, corresponding to a protein of 635 amino acid residues (M(r) = 65,208). The promoter site, which could be recognized by Escherichia coli RNA polymerase, was upstream from the gene, and the sequence adhering to the ribosome-binding sequence was found in front of the gene. The deduced amino acid sequence agreed with the N-terminal amino acid sequence of the purified PHB depolymerase from amino acid 28 onwards. Analysis of the deduced amino acid sequence revealed the domain structure of the protein; a signal peptide of 27 amino acids long was followed by a catalytic domain of about 400 amino acids, a fibronectin type III module sequence, and a putative substrate binding domain. The molecular mass (62,526) of the mature protein deduced from the nucleotide sequence was significantly lower than the value (95 kDa) estimated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but coincided well with the value (62,426) estimated from matrix-assisted laser desorption ionization mass spectra. By comparison of the primary structure with those of other PHB depolymerases, the substrate binding domain was found to consist of two domains, PHB-specific and poly(3-hydroxyvalerate)-specific ones, connected by a linker region. The PHB depolymerase gene was expressed in Escherichia coli under the control of the tac promoter. The enzyme expressed in E. coli was purified from culture broth and showed the same catalytic properties as the enzyme from A. faecalis.
