RT Journal Article SR Electronic(1) A1 Wu, Zhongqin A1 Qin, Lei A1 Walker, Virginia K.YR 2009 T1 Characterization and recombinant expression of a divergent ice nucleation protein from ‘Pseudomonas borealis’ JF Microbiology, VO 155 IS 4 SP 1164 OP 1169 DO https://doi.org/10.1099/mic.0.025114-0 PB Microbiology Society, SN 1465-2080, AB Isolates of ‘Pseudomonas borealis’ were recovered after ice-affinity selection of summer-collected soils. ‘P. borealis’ DL7 was further characterized and shown to have ice nucleation activity (INA), a property that allows the crystallization of ice at temperatures close to the melting point, effectively preventing the supercooling of water. INA was optimally detected after culturing at temperatures consistent with psychrophilic growth. The sequence encoding the ‘P. borealis’ ice nucleation protein (INP) was obtained using both PCR and chromosome walking. When expressed in Escherichia coli, the resulting inaPb recombinants had INA. The ‘P. borealis’ sequence, dubbed inaPb, is clearly related to previously cloned INP genes, but it shows greater divergence. Sequence analysis suggests that there are two opposite flat surfaces, one relatively hydrophobic that likely serves as an ice template, and the other that could function as a complementary face to facilitate interprotein interaction for ice-step formation., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.025114-0