Although the majority of structures in the PDB are of proteins that adopt higher order oligomers, it is not apparent in all cases why the quaternary form is critical for function. One example is the bacterial enzyme, dihydrodipicolinate synthase (DHDPS). The dimeric form of the enzyme contains all the structural requirements for catalysis, since dimerization completes the active site of each monomeric unit. However, the majority of DHDPS enzymes described to date form tetramers. Recent studies suggest that tetramerization is important for stabilizing protein dynamics at the dimeric interface where the active sites are located. This enables the enzyme to function at mesophilic (20-40°C) and thermophilic (>40°C) temperatures where protein dynamics are enhanced. However, it is hypothesized that DHDPS from a psychrophilic bacterium would exist as an active dimer, since protein dynamics are attenuated at cold (<20°C) temperatures. This study reports the structure and stability of the first psychrophilic DHDPS enzyme from the bacterium, Shewanella benthica, compared to mesophilic and thermophilic orthologs. Consistent with the hypothesis, our study demonstrates that S. benthica DHDPS exists as a functional dimer at biologically-relevant temperatures (≤12°C) both in solution and the crystal state, but aggregates non-specifically with attenuated catalytic function at temperatures ≥20°C. By contrast, control DHDPS enzymes from the mesophile Escherichia coli and thermophile Thermotoga maritima exist as functional tetramers at temperatures of ≤40°C and ≤80°C, respectively. Our results show that a synergy exists between attenuated protein oligomerization and cold environmental temperature, which offers insight into molecular evolution in enzyme quaternary structure and applications to industrial enzymology.