7D2A
CBM32 of AlyQ in complex with 4,5-unsaturated mannuronic acid
Summary for 7D2A
| Entry DOI | 10.2210/pdb7d2a/pdb |
| Descriptor | AlyQ, 4-deoxy-alpha-L-erythro-hex-4-enopyranuronic acid-(1-4)-alpha-L-gulopyranuronic acid, CALCIUM ION, ... (6 entities in total) |
| Functional Keywords | cbm32, alginate, sugar binding protein |
| Biological source | Persicobacter sp. CCB-QB2 |
| Total number of polymer chains | 1 |
| Total formula weight | 16704.72 |
| Authors | |
| Primary citation | Teh, A.H.,Sim, P.F.,Hisano, T. Structural basis for binding uronic acids by family 32 carbohydrate-binding modules. Biochem.Biophys.Res.Commun., 533:257-261, 2020 Cited by PubMed Abstract: The alginate lyase AlyQ from Persicobacter sp. CCB-QB2 is a three-domained enzyme with a carbohydrate-binding module (CBM) from family 32. The CBM32 domain, AlyQ, binds enzymatically cleaved but not intact alginate. Co-crystallisation of AlyQ with the cleaved alginate reveals that it binds to the 4,5-unsaturated mannuronic acid of the non-reducing end. The binding pocket contains a conserved R248 that interacts with the sugar's carboxyl group, as well as an invariant W303 that stacks against the unsaturated pyranose ring. Targeting specifically the non-reducing end is more efficient than the reducing end since the latter consists of a mixture of mannuronic acid and guluronic acid. AlyQ also seems unable to bind these two saturated sugars as they contain OH groups that will clash with the pocket. Docking analysis of YeCBM32, which binds oligogalacturonic acid, shows that the stacking of the pyranose ring is shifted in order to accommodate the sugar's axial C1-OH, and its R69 is accordingly elevated to bind the sugar's carboxyl group. Unlike AlyQ, YeCBM32's binding pocket is able to accommodate both saturated and unsaturated galacturonic acid. PubMed: 33010888DOI: 10.1016/j.bbrc.2020.09.064 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.57 Å) |
Structure validation
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