4XJ7

Crystal Structure of E112A Mutant of Stationary Phase Survival Protein (SurE) from Salmonella typhimurium soaked with AMP

Summary for 4XJ7

• Entry DOI: 10.2210/pdb4xj7/pdb
• Related: 4RYT 4RYU
• Descriptor: 5'/3'-nucleotidase SurE, MAGNESIUM ION, PHOSPHATE ION, ... (7 entities in total)
• Functional Keywords: stationary phase survival protein, domain swapping, rossmann fold like, phosphatase, hydrolase
• Biological source: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• Total number of polymer chains: 4
• Total formula weight: 115651.29

Authors

Mathiharan, Y.K.,Murthy, M.R.N. (deposition date: 2015-01-08, release date: 2015-09-09, Last modification date: 2023-11-08)

Primary citation

Mathiharan, Y.K.,Savithri, H.S.,Murthy, M.R.
Insights into stabilizing interactions in the distorted domain-swapped dimer of Salmonella typhimurium survival protein.
Acta Crystallogr.,Sect.D, 71:1812-1823, 2015

PubMed Abstract: The survival protein SurE from Salmonella typhimurium (StSurE) is a dimeric protein that functions as a phosphatase. SurE dimers are formed by the swapping of a loop with a pair of β-strands and a C-terminal helix between two protomers. In a previous study, the Asp230 and His234 residues were mutated to Ala to abolish a hydrogen bond that was thought to be crucial for C-terminal helix swapping. These mutations led to functionally inactive and distorted dimers in which the two protomers were related by a rotation of 167°. New salt bridges involving Glu112 were observed in the dimeric interface of the H234A and D230A/H234A mutants. To explore the role of these salt bridges in the stability of the distorted structure, E112A, E112A/D230A, E112A/H234A, E112A/D230A/H234A, R179L/H180A/H234A and E112A/R179L/H180A/H234A mutants were constructed. X-ray crystal structures of the E112A, E112A/H234A and E112A/D230A mutants could be determined. The dimeric structures of the E112A and E112A/H234A mutants were similar to that of native SurE, while the E112A/D230A mutant had a residual rotation of 11° between the B chains upon superposition of the A chains of the mutant and native dimers. The native dimeric structure was nearly restored in the E112A/H234A mutant, suggesting that the new salt bridge observed in the H234A and D230A/H234A mutants was indeed responsible for the stability of their distorted structures. Catalytic activity was also restored in these mutants, implying that appropriate dimeric organization is necessary for the activity of SurE.

PubMed: 26327371
DOI: 10.1107/S1399004715011992

Experimental method

X-RAY DIFFRACTION (1.6 Å)