Novel molecular architecture of the multimeric archaeal PEP-synthase homologue (MAPS) from Staphylothermus marinus.

The phosphoenolpyruvate (PEP)-synthases belong to the family of structurally and functionally related PEP-utilizing enzymes. The only archaeal member of this family characterized thus far is the Multimeric Archaeal PEP-Synthase homologue from Staphylothermus marinus (MAPS). This protein complex differs from the bacterial and eukaryotic representatives characterized to date in its homomultimeric, as opposed to dimeric or tetrameric, structure.

Structural studies on the 2.25-MDa homomultimeric phosphoenolpyruvate synthase from Staphylothermus marinus.

The phosphoenolpyruvate synthase of the hyperthermophilic archaeon Staphylothermus marinus forms an unusually large homomultimeric complex of 93 kDa subunits. Electron image analysis of negatively stained and low-dose unstained preparations showed that the complex has a single, stable characteristic view and a well-preserved core with threefold rotational symmetry. The periphery of the assembly is composed of a nebulous, possibly flexible, component.

Primary structure of a multimeric protein, homologous to the PEP-utilizing enzyme family and isolated from a hyperthermophilic archaebacterium.

A large protein complex (approx. 2000 kDa) was found in the cytosol of the hyperthermophilic archaebacterium Staphylothermus marinus. The purified protein was shown to be a homomultimer of 93 kDa subunits, the primary structure of which was determined by nucleotide sequence analysis.