Crystal Structure of Hypothetical Fructose-Specific EIIB from Escherichia coli
| Autor: | Edward A. Berry, Gil-Ja Jhon, Dong Hae Shin, Jimin Park, Jooyoung Lee, Mi-Sun Kim, Keehyung Joo |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
frwD Models Molecular Protein Folding functional cysteine Cellobiose Fructose medicine.disease_cause Crystallography X-Ray Article Protein Structure Secondary Conserved sequence Substrate Specificity 03 medical and health sciences chemistry.chemical_compound fructose specific enzyme EIIB Catalytic Domain medicine PTS permease Escherichia coli Moiety Amino Acid Sequence Cysteine Phosphoenolpyruvate Sugar Phosphotransferase System Molecular Biology Peptide sequence Conserved Sequence X-ray crystallography PTS system 030102 biochemistry & molecular biology biology Escherichia coli Proteins Active site Cell Biology General Medicine PEP group translocation 030104 developmental biology Biochemistry chemistry biology.protein Protein folding |
| Zdroj: | Molecules and Cells |
| ISSN: | 0219-1032 1016-8478 |
| Popis: | We have solved the crystal structure of a predicted fructose-specific enzyme IIB(fruc) from Escherichia coli (EcEIIB(fruc)) involved in the phosphoenolpyruvate-carbohydrate phosphotransferase system transferring carbohydrates across the cytoplasmic membrane. EcEIIB(fruc) belongs to a sequence family with more than 5,000 sequence homologues with 25-99% amino-acid sequence identity. It reveals a conventional Rossmann-like α-β-α sandwich fold with a unique β-sheet topology. Its C-terminus is longer than its closest relatives and forms an additional β-strand whereas the shorter C-terminus is random coil in the relatives. Interestingly, its core structure is similar to that of enzyme IIB(cellobiose) from E. coli (EcIIB(cel)) transferring a phosphate moiety. In the active site of the closest EcEIIB(fruc) homologues, a unique motif CXXGXAHT comprising a P-loop like architecture including a histidine residue is found. The conserved cysteine on this loop may be deprotonated to act as a nucleophile similar to that of EcIIB(cel). The conserved histidine residue is presumed to bind the negatively charged phosphate. Therefore, we propose that the catalytic mechanism of EcEIIB(fruc) is similar to that of EcIIB(cel) transferring phosphoryl moiety to a specific carbohydrate. |
| Databáze: | OpenAIRE |
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