Complete genome sequence of the aerobic, heterotroph Marinithermus hydrothermalis type strain (T1T) from a deep-sea hydrothermal vent chimney

Standards in Genomic Sciences (Impact Factor: 3.17). 03/2012; 6(1):21-30. DOI: 10.4056/sigs.2435521
Source: PubMed


Marinithermus hydrothermalis Sako et al. 2003 is the type species of the monotypic genus Marinithermus. M. hydrothermalis T1T was the first isolate within the phylum “Thermus-Deinococcus” to exhibit optimal growth under a salinity equivalent to that of sea water and to have an absolute requirement for NaCl for growth. M. hydrothermalis T1T is of interest because it may provide a new insight into the ecological significance of the aerobic, thermophilic decomposers in the circulation of organic compounds in deep-sea hydrothermal vent ecosystems. This is the first completed genome sequence of a member of the genus Marinithermus and the seventh sequence from the family Thermaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,269,167 bp long genome with its 2,251 protein-coding and 59 RNA genes is a part of the Genomic
Encyclopedia of
Bacteria and
Archaea project.

Download full-text


Available from: Johannes Sikorski
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thermus thermophilus exhibits hypersensitivity to a lysine analog, (S)-2-aminoethyl-cysteine (AEC). Cosmid libraries were constructed using genomes from two AEC-resistant mutants, AT10 and AT14, and the cosmids that conferred AEC resistance on the wild-type strain were isolated. When the cosmid library for mutant AT14 was screened, two independent cosmids, conferring partial AEC resistance to the wild type, were obtained. Two cosmids carried a common genomic region from TTC0795 to TTC0810. This region contains genes encoding an ATP-binding cassette (ABC) transporter consisting of TTC0806/TTC0795, using TTC0807 as the periplasmic substrate-binding protein. Sequencing revealed that AT14 carries mutations in TTC0795 and TTC0969, causing decreases in the thermostability of the products. TTC0969 encodes the nucleotide-binding protein of a different ABC transporter consisting of TTC0967/TTC0968/TTC0969/TTC0970 using TTC0966 as the periplasmic substrate-binding protein. By similar screening for cosmids constructed for the mutant AT10, mutations were found at TTC0807 and TTC0969. Mutation in either of the transporter components gave partial resistance to AEC in the wild-type strain, while mutations of both transporters conferred complete AEC resistance. This result indicates that both transporters are involved in AEC uptake in T. thermophilus. To elucidate the mechanism of AEC uptake, crystal structures of TTC0807 were determined in several substrate-binding forms. The structures revealed that TTC0807 recognizes various basic amino acids by changing the side-chain conformation of Glu19, which interacts with the side-chain amino groups of the substrates.
    Preview · Article · Jun 2013 · Journal of bacteriology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Some strategies have been found in prokaryotes to adapt to extreme environments, where physicochemical values are higher or lower than that which is considered standard for most living organisms. Saline environments represent a challenge to the survival of microorganisms due to the low water activity and the high concentrations of inorganic ions that are toxic to cellular metabolism. Microorganisms respond to osmotic stress mostly by accumulating compatible solutes, either by uptake from the medium or by de novo synthesis. These osmotically active molecules adjust the cellular osmotic potential in order to preserve the positive turgor pressure required for cell division. Compatible solutes are low-molecular mass organic compounds that can be accumulated in high (molar) amounts without negatively interfering with cellular metabolism. The diversity of compatible solutes is large but falls into only a few major chemical categories; while some are widely distributed in nature others seem to be exclusively present in specific groups of organisms. This chapter discusses the diversity and distribution of sugar derivate compatible solutes, namely, trehalose and sugar-glycerate osmolytes, as well as the increasing knowledge of the genes and pathways involved in their synthesis in microorganisms that live in hot and saline environments. The recent discovery that some marine bacteria accumulated GG and MGG to cope with osmotic stress has driven research for the full characterization of this biocatalysis process for biotechnological purposes.
    No preview · Chapter · Dec 2013