Abstract:
Metagenomic library screening, by functional or sequence analysis, has become an
established method for the identification of novel genes and gene products, including
genetic elements implicated in microbial stress response and adaptation. We have
identified, using a sequence based approach, a fosmid clone from an Antarctic desert
soil metagenome library containing a novel gene which codes for a protein homologous
to a Water Hypersensitive domain (WHy). The WHy domain is typically found as a
component of specific LEA (Late Embryogenesis Abundant) proteins, particularly the
LEA-14 (LEA-8) variants, which occur widely in plants, nematodes, bacteria and archaea and which are typically induced by exposure to stress conditions. The novel
Why-like protein, (165 amino acid, 18.6 kDa) exhibits a largely invariant NPN motif at
the N-terminus and has high sequence identity to genes identified in Pseudomonas
genomes. Expression of this protein in E. coli significantly protected the recombinant
host against cold and freeze stress.
