Milk utilization genes

There are two main classes of utilization genes identified in the B. infantis genome. Hydrolytic genes that degrade milk molecules, as well as transport-associated solute binding proteins. Among the hydrolytic genes, there are the four glycosyl hydrolases predicted to be active on the HMO structure as well as urease genes active on milk urea. The solute binding proteins (SBPs) all belong to family 1 which includes oligosaccharide binding proteins associated with ABC transporters. Although some of these SBPs bind HMO glycans it is currently unclear if all of them participate in HMO transport.

For more detail please refer to: Sela , D.A. et al., PNAS (2008) PMID:19033196

A phylogenetic distribution of these genes in other gut microbes can be found here.

 

Some abbreviations:

HMO- Human Milk Oligosaccharide

MG- Milk Glyconjugate (includes glycolipids and glycoproteins)

GOS- Galactooligosaccharide

SBP- Solute Binding Protein

 

Dowload a spreadsheet of these genes here:  milk.genes.infantis.xls

 

Hydrolytic enzymes

 

Locus Tag Product Name Length (AA) Enzyme Active On Notes
Blon_0646 Sialidase 760 EC:3.2.1.18 sialylated glycans (HMO; MG)
Blon_2348 Sialidase 394 EC:3.2.1.18 sialylated glycans (HMO; MG) Encoded in HMO cluster
Blon_0248 Alpha-L-fucosidase 449 EC:3.2.1.51 fucosylated glycans (HMO; MG)
Blon_0426 Alpha-L-fucosidase 449 EC:3.2.1.51 fucosylated glycans (HMO; MG)
Blon_2336 Alpha-L-fucosidase 478 EC:3.2.1.51 fucosylated glycans (HMO; MG) Encoded in HMO cluster
Blon_0268 Beta-galactosidase 606 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose)
Blon_0346 Beta-galactosidase 674 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose)
Blon_2016 Beta-galactosidase 691 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose)
Blon_2123 Beta-galactosidase 720 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose)
Blon_2334 Beta-galactosidase 1023 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose) Encoded in HMO cluster
Blon_2416 Beta-galactosidase 706 EC:3.2.1.23 galactosides (HMO; MG; GOS; lactose)
Blon_0459 Beta-hexosaminidase 673 EC:3.2.1.52 N-acetylglucosides/N-acetylgalactosides (HMO; MG)
Blon_0732 Beta-hexosaminidase 651 EC:3.2.1.52 N-acetylglucosides/N-acetylgalactosides (HMO; MG)
Blon_2355 Beta-hexosaminidase 651 EC:3.2.1.52 N-acetylglucosides/N-acetylgalactosides (HMO; MG) Encoded in HMO cluster
Blon_2174 Lacto-N-biose phosphorylase 751 EC:2.4.1.211 Lacto-N-biose/Galacto-N-biose
Blon_0110 urease, γ subunit 232 EC:3.5.1.5 milk urea
Blon_0111 urease, α subunit 573 EC:3.5.1.5 milk urea
Blon_0112 UreE, accessory protein 221 EC:3.5.1.5 milk urea
Blon_0113 UreF, accessory protein 273 EC:3.5.1.5 milk urea
Blon_0114 UreG, accessory protein 203 EC:3.5.1.5 milk urea
Blon_0115 UreD, accessory protein 284 EC:3.5.1.5 milk urea

 

Potential oligosaccharide binding proteins

Locus Tag Product Name Length (AA) Active On Notes
Blon_0043 SBP, family 1 435 oligosaccharides or other solutes
Blon_0321 SBP, family 1 388 oligosaccharides or other solutes
Blon_0343 SBP, family 1 469 oligosaccharides or other solutes
Blon_0375 SBP, family 1 421 oligosaccharides or other solutes
Blon_0883 SBP, family 1 445 oligosaccharides or other solutes
Blon_2015 SBP, family 1 473 oligosaccharides or other solutes
Blon_2061 SBP, family 1 535 oligosaccharides or other solutes
Blon_2177 SBP, family 1 438 oligosaccharides or other solutes
Blon_2202 SBP, family 1 460 oligosaccharides or other solutes
Blon_2344 SBP, family 1 530 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2347 SBP, family 1 531 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2350 SBP, family 1 530 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2351 SBP, family 1 534 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2352 SBP, family 1 532 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2354 SBP, family 1 531 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2357 SBP, family 1 430 oligosaccharides or other solutes Encoded in HMO cluster
Blon_2367 SBP, family 1 459 oligosaccharides or other solutes
Blon_2380 SBP, family 1 426 oligosaccharides or other solutes
Blon_2414 SBP, family 1 415 oligosaccharides or other solutes
Blon_2444 SBP, family 1 448 oligosaccharides or other solutes
Blon_2458 SBP, family 1 429 oligosaccharides or other solutes