Structural and functional characterization of a cold adapted TPM-domain with ATPase/ADPase activity

MARÍA L. CERUTTI; LISANDRO OTERO; CLARA SMAL; LEONARDO PELLIZA; FERNANDO A. GOLDBAUM; SEBASTIÁN KLINKE *CO-CORRESPONDING AUTHOR; MARTIN ARAN *CO-CORRESPONDING AUTHOR

JOURNAL OF STRUCTURAL BIOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2017 vol. 197 p. 201 - 209

1047-8477

*CO-CORRESPONDING AUTHORS: SEBASTIAN KLINKE y MARTIN ARAN. The Pfam PF04536 TPM_phosphatase family is abroadly conserved family of domains found across prokaryotes, plants andinvertebrates. Despite having a similar protein fold, members of this familyhave been implicated in diverse cellular processes and found in variedsubcellular localizations. Very recently, the biochemical characterization oftwo evolutionary divergent TPM domains has shown that they are able to hydrolyzephosphate groups from different substrates. However, there are still incorrectfunctional annotations and uncertain relationships between the structure andfunction of this family of domains. BA41 is an uncharacterized single-passtransmembrane protein from the Antarctic psychrotolerant bacterium Bizioniaargentinensis with a predicted compact extracytoplasmic TPM domain and aC-terminal cytoplasmic low complexity region. To shed light on the structuralproperties that enable TPM domains to adopt divergent roles, we here accomplisha comprehensive structural and functional characterization of the central TPMdomain of BA41 (BA41-TPM). Contrary to its predicted function as abeta-propeller methanol dehydrogenase, light scattering and crystallographicstudies showed that BA41-TPM behaves as a globular monomeric protein and adoptsa conserved Rossmann fold, typically observed in other TPM domain structures.Although the crystal structure reveals the conservation of residues involved insubstrate binding, no putative catalytic or intramolecular metal ions weredetected. Most important, however, extensive biochemical studies demonstratedthat BA41-TPM has hydrolase activity against ADP, ATP, and other di- andtriphosphate nucleotides and shares properties of cold-adapted enzymes. Therole of BA41 in extracellular ATP-mediated signaling pathways and itsoccurrence in environmental and pathogenic microorganisms is discussed.