Journal article
Raffinose family oligosaccharide utilisation by probiotic bacteria: insight into substrate recognition, molecular architecture and diversity of GH36 alpha-galactosidases
Department of Systems Biology, Technical University of Denmark1
Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark2
Technical University of Denmark3
DuPont Nutrition and Health4
North Carolina State University5
Aix-Marseille Université6
University of Copenhagen7
The organisation of genes conferring utilisation of raffinose family oligosaccharides (RFOs) has been analysed in several probiotic bacteria from the Bifidobacterium and Lactobacillus genera. Glycoside hydrolase family 36 (GH36) alpha-galatosidase encoding genes occur together with sugar transport systems of the glycoside-pentoside-hexuronide cation symporter family (GPH), sugar phosphotransferase systems (PTSs) or ATP-binding cassette systems (ABCs) highlighting the diversity of RFO uptake.
The GH36 genes are often clustered together with sucrose hydrolases or phosphorylases ensuring the degradation of RFO to monosaccharides. Differential proteomics and transcriptomics data from our laboratories implicated ABC transporters in the uptake of RFO in both Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bl-04.
Interestingly, only one of three GH36 encoding genes in B. animalis subsp. lactis Bl-04 was upregulated upon growth on RFO, suggesting that the other two gene products may have different specificities. The structure of the GH36 homotetrameric alpha-galactosidase from L. acidophilus NCFM (LaMel36A) was determined in complex with galactose bound in the active site to 1.58 angstrom.
Differences in the N- and C-terminal domains of the LaMel36A monomer distinguished it from the monomeric TmGalA from Thermotoga maritima providing a structural rationale for the observed difference in oligomeric states of the two enzymes. Tetramerisation of LaMel36A creates a narrow and deep active site pocket between three monomers, which explains the preference of tetrameric GH36 enzymes for RFO and their lack of activity on polymeric galacto(gluco) mannan.
Finally, GH36 was divided into four subgroups based on active site motifs, which illuminates functional and structural diversity in the family and aids further annotation of emerging sequences.
| Language: | English |
|---|---|
| Publisher: | Taylor & Francis |
| Year: | 2012 |
| Pages: | 316-325 |
| ISSN: | 10292446 and 10242422 |
| Types: | Journal article |
| DOI: | 10.3109/10242422.2012.674717 |
| ORCIDs: | 0000-0002-5135-0882 , Abou Hachem, Maher , Fredslund, Folmer , Hansen, Morten Ejby and Svensson, Birte |
03502, Genetics - General 10062, Biochemistry studies - Nucleic acids, purines and pyrimidines 10068, Biochemistry studies - Carbohydrates 10802, Enzymes - General and comparative studies: coenzymes 31000, Physiology and biochemistry of bacteria 31500, Genetics of bacteria and viruses Actinomycetes and Related Organisms Eubacteria Bacteria Microorganisms (Bacteria, Eubacteria, Microorganisms) - Irregular Nonsporing Gram-Positive Rods [08890] Bifidobacterium animalis lactis subspecies strain-Bl-04 Anaerobic Gram-Negative Rods Eubacteria Bacteria Microorganisms (Bacteria, Eubacteria, Microorganisms) - Bacteroidaceae [06901] Thermotoga maritima species Biochemistry and Molecular Biophysics Enzymology Eubacteria Bacteria Microorganisms (Bacteria, Eubacteria, Microorganisms) - Regular Nonsporing Gram-Positive Rods [07830] Lactobacillus acidophilus species strain-NCFM Facultatively Anaerobic Gram-Negative Rods Eubacteria Bacteria Microorganisms (Bacteria, Eubacteria, Microorganisms) - Enterobacteriaceae [06702] Escherichia coli species GenBank sequence data Mel36A monomer N-terminal domain, C-terminal domain Molecular Genetics SDG 3 - Good Health and Well-being alpha-galatosidase functional diversity galactomannan 11078-30-1 galactose 26566-61-0 genes glycoside hydrolase family 36 GH36 molecular architecture monosaccharides phosphorylase 9035-74-9 EC 2.4.1.1 probiotic raffinose family oligosaccharides RFO structural diversity substrate recognition sucrose hydrolases
