Genomic and Expression Analyses of Cold-Adapted Microorganisms.

Abstract

Contents 7.1 Introduction 7.2 Ecological evidence of bacterial adaptation to cold 7.2.1 Characteristics of cold environments and implications for microbial ecology 7.2.2 Ecological adaptation in Exiguobacterium spp. and Psychrobacter spp. 7.3 Gene Expression Responses to the Cold 7.3.1 Fundamentals of Gene Expression Responses to Cold 7.3.2 Acclimation for Life in Cold Habitats 7.3.2.1 Translation and Chaperone Proteins: Safeguarding the functional units of cellular physiology 7.3.2.2 Carbon and Energy metabolism: resource efficiency over long generation times 7.3.2.3 Amino Acid Biosynthesis: Species-specific responses to species-specific deficiencies 7.3.2.4 Compatible solutes: a concomitant response in cryoenvironments 7.3.2.5 Membrane fluidity: A major role in the overall metabolic rate at temperature 7.3.2.6 The cell wall at low temperature: A poorly understood growth rate determinant 7.3.2.7 Transporters: The balance between local nutrient uptake and depletion 7.3.2.8 Genome plasticity. The potential role of transposases and repeated sequences. 7.4 Protein adaptations to cold 7.4.1 The low temperature challenge 7.4.2 The stability activity relationship 7.4.3 Structural features of cold adapted enzymes. 7.4.4 Hydrophobic interactions 7.4.5 Electrostatic interactions 7.4.5.1 Arginine 7.4.5.2 Acidic residues 7.4.6 Structural elements 7.4.6.1 α-helices and β-sheets 7.4.6.2 Proline and Glycine 7.4.6.3 Disordered regions 7.5 Comparison of cold- and warm-adapted Exiguobacterium strains 7.5.1 Phylogeny reflects adaptations to environmental conditions 7.5.2 Genomic comparison of two strains 7.6 Summary and future directions