First time at Proteopedia? Click on the green links: they change the 3D image. Click and drag the molecules. Proteopedia is a 3D, interactive encyclopedia of proteins, RNA, DNA and other molecules. With a free user account, you can edit pages in Proteopedia. Visit the Main Page to learn more.


From Proteopedia

Jump to: navigation, search

3k8m, resolution 2.50Å ()
Ligands: , , , ,
Non-Standard Residues:
Gene: BT_3698, SusG (Bacteroides thetaiotaomicron)
Related: 3k8k, 3k8l
Resources: FirstGlance, OCA, PDBsum, RCSB
Coordinates: save as pdb, mmCIF, xml


Crystal structure of SusG with acarbose

Publication Abstract from PubMed

SusG is an alpha-amylase and part of a large protein complex on the outer surface of the bacterial cell and plays a major role in carbohydrate acquisition by the animal gut microbiota. Presented here, the atomic structure of SusG has an unusual extended, bilobed structure composed of amylase at one end and an unprecedented internal carbohydrate-binding motif at the other. Structural studies further demonstrate that the carbohydrate-binding motif binds maltooligosaccharide distal to, and on the opposite side of, the amylase catalytic site. SusG has an additional starch-binding site on the amylase domain immediately adjacent to the active cleft. Mutagenesis analysis demonstrates that these two additional starch-binding sites appear to play a role in catabolism of insoluble starch. However, elimination of these sites has only a limited effect, suggesting that they may have a more important role in product exchange with other Sus components.

SusG: a unique cell-membrane-associated alpha-amylase from a prominent human gut symbiont targets complex starch molecules., Koropatkin NM, Smith TJ, Structure. 2010 Feb 10;18(2):200-15. PMID:20159465

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

About this Structure

3k8m is a 2 chain structure with sequence from Bacteroides thetaiotaomicron. Full crystallographic information is available from OCA.

See Also


  • Koropatkin NM, Smith TJ. SusG: a unique cell-membrane-associated alpha-amylase from a prominent human gut symbiont targets complex starch molecules. Structure. 2010 Feb 10;18(2):200-15. PMID:20159465 doi:10.1016/j.str.2009.12.010

Proteopedia Page Contributors and Editors (what is this?)


Personal tools