Structure of a product bound plant phosphataseStructure of a product bound plant phosphatase

Structural highlights

4kyq is a 1 chain structure with sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.64Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

LSF2_ARATH Starch-associated phosphoglucan phosphatase that can release phosphate from the C3 glucan position. Probably participates in the regulation of starch degradation.[1]

Publication Abstract from PubMed

Starch is a water-insoluble, Glc-based biopolymer that is used for energy storage and is synthesized and degraded in a diurnal manner in plant leaves. Reversible phosphorylation is the only known natural starch modification and is required for starch degradation in planta. Critical to starch energy release is the activity of glucan phosphatases; however, the structural basis of dephosphorylation by glucan phosphatases is unknown. Here, we describe the structure of the Arabidopsis thaliana starch glucan phosphatase LIKE SEX FOUR2 (LSF2) both with and without phospho-glucan product bound at 2.3A and 1.65A, respectively. LSF2 binds maltohexaose-phosphate using an aromatic channel within an extended phosphatase active site and positions maltohexaose in a C3-specific orientation, which we show is critical for the specific glucan phosphatase activity of LSF2 toward native Arabidopsis starch. However, unlike other starch binding enzymes, LSF2 does not possess a carbohydrate binding module domain. Instead we identify two additional glucan binding sites located within the core LSF2 phosphatase domain. This structure is the first of a glucan-bound glucan phosphatase and provides new insights into the molecular basis of this agriculturally and industrially relevant enzyme family as well as the unique mechanism of LSF2 catalysis, substrate specificity, and interaction with starch granules.

Structure of the Arabidopsis Glucan Phosphatase LIKE SEX FOUR2 Reveals a Unique Mechanism for Starch Dephosphorylation.,Meekins DA, Guo HF, Husodo S, Paasch BC, Bridges TM, Santelia D, Kotting O, Vander Kooi CW, Gentry MS Plant Cell. 2013 Jul 5. PMID:23832589[2]

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

References

  1. Santelia D, Kotting O, Seung D, Schubert M, Thalmann M, Bischof S, Meekins DA, Lutz A, Patron N, Gentry MS, Allain FH, Zeeman SC. The phosphoglucan phosphatase like sex Four2 dephosphorylates starch at the C3-position in Arabidopsis. Plant Cell. 2011 Nov;23(11):4096-111. doi: 10.1105/tpc.111.092155. Epub 2011 Nov , 18. PMID:22100529 doi:10.1105/tpc.111.092155
  2. Meekins DA, Guo HF, Husodo S, Paasch BC, Bridges TM, Santelia D, Kotting O, Vander Kooi CW, Gentry MS. Structure of the Arabidopsis Glucan Phosphatase LIKE SEX FOUR2 Reveals a Unique Mechanism for Starch Dephosphorylation. Plant Cell. 2013 Jul 5. PMID:23832589 doi:10.1105/tpc.113.112706

4kyq, resolution 1.64Å

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