TY - JOUR
T1 - The globins of cold-adapted Pseudoalteromonas haloplanktis TAC125
T2 - From the structure to the physiological functions
AU - Giordano, Daniela
AU - Coppola, Daniela
AU - Russo, Roberta
AU - Tinajero-Trejo, Mariana
AU - di Prisco, Guido
AU - Lauro, Federico
AU - Ascenzi, Paolo
AU - Verde, Cinzia
PY - 2013
Y1 - 2013
N2 - Evolution allowed Antarctic microorganisms to grow successfully under extreme conditions (low temperature and high O2 content), through a variety of structural and physiological adjustments in their genomes and development of programmed responses to strong oxidative and nitrosative stress. The availability of genomic sequences from an increasing number of cold-adapted species is providing insights to understand the molecular mechanisms underlying crucial physiological processes in polar organisms. The genome of Pseudoalteromonas haloplanktis TAC125 contains multiple genes encoding three distinct truncated globins exhibiting the 2/2 α-helical fold. One of these globins has been extensively characterised by spectroscopic analysis, kinetic measurements and computer simulation. The results indicate unique adaptive structural properties that enhance the overall flexibility of the protein, so that the structure appears to be resistant to pressure-induced stress. Recent results on a genomic mutant strain highlight the involvement of the cold-adapted globin in the protection against the stress induced by high O2 concentration. Moreover, the protein was shown to catalyse peroxynitrite isomerisation in vitro. In this review, we first summarise how cold temperatures affect the physiology of microorganisms and focus on the molecular mechanisms of cold adaptation revealed by recent biochemical and genetic studies. Next, since only in a very few cases the physiological role of truncated globins has been demonstrated, we also discuss the structural and functional features of the cold-adapted globin in an attempt to put into perspective what has been learnt about these proteins and their potential role in the biology of cold-adapted microorganisms.
AB - Evolution allowed Antarctic microorganisms to grow successfully under extreme conditions (low temperature and high O2 content), through a variety of structural and physiological adjustments in their genomes and development of programmed responses to strong oxidative and nitrosative stress. The availability of genomic sequences from an increasing number of cold-adapted species is providing insights to understand the molecular mechanisms underlying crucial physiological processes in polar organisms. The genome of Pseudoalteromonas haloplanktis TAC125 contains multiple genes encoding three distinct truncated globins exhibiting the 2/2 α-helical fold. One of these globins has been extensively characterised by spectroscopic analysis, kinetic measurements and computer simulation. The results indicate unique adaptive structural properties that enhance the overall flexibility of the protein, so that the structure appears to be resistant to pressure-induced stress. Recent results on a genomic mutant strain highlight the involvement of the cold-adapted globin in the protection against the stress induced by high O2 concentration. Moreover, the protein was shown to catalyse peroxynitrite isomerisation in vitro. In this review, we first summarise how cold temperatures affect the physiology of microorganisms and focus on the molecular mechanisms of cold adaptation revealed by recent biochemical and genetic studies. Next, since only in a very few cases the physiological role of truncated globins has been demonstrated, we also discuss the structural and functional features of the cold-adapted globin in an attempt to put into perspective what has been learnt about these proteins and their potential role in the biology of cold-adapted microorganisms.
KW - Antarctic marine bacterium
KW - Cold-adapted bacterial globin
KW - Pseudoalteromonas haloplanktis TAC125
KW - Truncated haemoglobins
UR - http://www.scopus.com/inward/record.url?scp=84884196793&partnerID=8YFLogxK
U2 - 10.1016/B978-0-12-407693-8.00008-X
DO - 10.1016/B978-0-12-407693-8.00008-X
M3 - Article
C2 - 24054800
AN - SCOPUS:84884196793
SN - 0065-2911
VL - 63
SP - 329
EP - 389
JO - Advances in Microbial Physiology
JF - Advances in Microbial Physiology
ER -