Structural highlights
Publication Abstract from PubMedHumans have co-evolved with a dense community of microbial symbionts that inhabit the lower intestine. In the colon, secreted mucus creates a barrier that separates these microorganisms from the intestinal epithelium(1). Some gut bacteria are able to utilize mucin glycoproteins, the main mucus component, as a nutrient source. However, it remains unclear which bacterial enzymes initiate degradation of the complex O-glycans found in mucins. In the distal colon, these glycans are heavily sulfated, but specific sulfatases that are active on colonic mucins have not been identified. Here we show that sulfatases are essential to the utilization of distal colonic mucin O-glycans by the human gut symbiont Bacteroides thetaiotaomicron. We characterized the activity of 12 different sulfatases produced by this species, showing that they are collectively active on all known sulfate linkages in O-glycans. Crystal structures of three enzymes provide mechanistic insight into the molecular basis of substrate specificity. Unexpectedly, we found that a single sulfatase is essential for utilization of sulfated O-glycans in vitro and also has a major role in vivo. Our results provide insight into the mechanisms of mucin degradation by a prominent group of gut bacteria, an important process for both normal microbial gut colonization(2) and diseases such as inflammatory bowel disease(3). A single sulfatase is required to access colonic mucin by a gut bacterium.,Luis AS, Jin C, Pereira GV, Glowacki RWP, Gugel SR, Singh S, Byrne DP, Pudlo NA, London JA, Basle A, Reihill M, Oscarson S, Eyers PA, Czjzek M, Michel G, Barbeyron T, Yates EA, Hansson GC, Karlsson NG, Cartmell A, Martens EC Nature. 2021 Oct;598(7880):332-337. doi: 10.1038/s41586-021-03967-5. Epub 2021, Oct 6. PMID:34616040[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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