5Z2K

Structure of S38A mutant Mn-bound periplasmic metal binding protein from candidatus liberibacter asiaticus

Summary for 5Z2K

• Entry DOI: 10.2210/pdb5z2k/pdb
• Descriptor: Periplasmic solute binding protein, MANGANESE (II) ION, SULFATE ION, ... (6 entities in total)
• Functional Keywords: abc transporter, periplasmic solute binding protein, metal binding protein
• Biological source: Liberibacter asiaticus (strain psy62)
• Total number of polymer chains: 1
• Total formula weight: 32030.98

Authors

Saini, G.,Sharma, N.,Dalal, V.,Kumar, P.,Sharma, A.K. (deposition date: 2018-01-02, release date: 2018-10-03, Last modification date: 2023-11-22)

Primary citation

Saini, G.,Sharma, N.,Dalal, V.,Warghane, A.,Ghosh, D.K.,Kumar, P.,Sharma, A.K.
The analysis of subtle internal communications through mutation studies in periplasmic metal uptake protein CLas-ZnuA2
J. Struct. Biol., 204:228-239, 2018

PubMed Abstract: The subtle internal communications through an intricate network of interactions play a key role in metal-binding and release in periplasmic metal uptake proteins of cluster A-I family, a component of ABC transport system. These proteins have evolved different mechanisms of metal-binding and release through sequence and thereby structure-function divergence. The CLas-ZnuA2 from Candidatus Liberibacter asiaticus (CLA), in previous studies, showed a lower metal-binding affinity. The subtle communications within and between domains from crystal structure analysis revealed that protein seems to prefer a metal-free state. The unique features of CLas-ZnuA2 included a highly restrained loop L3 and presence of a proline in linker helix. In present work, S38A and Y68F mutants were studied as they play an important role during metal-binding in CLas-ZnuA2. The mutations in linker helix could not be studied as the expressed protein was not soluble and in most cases degraded with time. The crystal structure analysis of (S38A and Y68F) mutants in metal-free and metal-bound forms showed variations in interactions, an increase in number of alternate conformations and distortions in secondary structure elements, despite a similar overall structure, suggesting alterations in internal communications. The results suggested that any change in critical residues could alter the subtle internal communications and result in disturbing the fine-tuned structure required for optimal functioning.

PubMed: 30125692
DOI: 10.1016/j.jsb.2018.08.013

Experimental method

X-RAY DIFFRACTION (1.8 Å)