Article

Biosynthesis of ether-type polar lipids in archaea and evolutionary considerations.

Department of Chemistry, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
Microbiology and Molecular Biology Reviews (Impact Factor: 15.26). 04/2007; 71(1):97-120. DOI: 10.1128/MMBR.00033-06
Source: PubMed

ABSTRACT This review deals with the in vitro biosynthesis of the characteristics of polar lipids in archaea along with preceding in vivo studies. Isoprenoid chains are synthesized through the classical mevalonate pathway, as in eucarya, with minor modifications in some archaeal species. Most enzymes involved in the pathway have been identified enzymatically and/or genomically. Three of the relevant enzymes are found in enzyme families different from the known enzymes. The order of reactions in the phospholipid synthesis pathway (glycerophosphate backbone formation, linking of glycerophosphate with two radyl chains, activation by CDP, and attachment of common polar head groups) is analogous to that of bacteria. sn-Glycerol-1-phosphate dehydrogenase is responsible for the formation of the sn-glycerol-1-phosphate backbone of phospholipids in all archaea. After the formation of two ether bonds, CDP-archaeol acts as a common precursor of various archaeal phospholipid syntheses. Various phospholipid-synthesizing enzymes from archaea and bacteria belong to the same large CDP-alcohol phosphatidyltransferase family. In short, the first halves of the phospholipid synthesis pathways play a role in synthesis of the characteristic structures of archaeal and bacterial phospholipids, respectively. In the second halves of the pathways, the polar head group-attaching reactions and enzymes are homologous in both domains. These are regarded as revealing the hybrid nature of phospholipid biosynthesis. Precells proposed by Wächtershäuser are differentiated into archaea and bacteria by spontaneous segregation of enantiomeric phospholipid membranes (with sn-glycerol-1-phosphate and sn-glycerol-3-phosphate backbones) and the fusion and fission of precells. Considering the nature of the phospholipid synthesis pathways, we here propose that common phospholipid polar head groups were present in precells before the differentiation into archaea and bacteria.

0 Followers
 · 
151 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A systematic comparative genomic analysis of all archaeal membrane proteins that have been projected to the last archaeal common ancestor gene set led to the identification of several novel components of predicted secretion, membrane remodeling, and protein glycosylation systems. Among other findings, most crenarchaea have been shown to encode highly diverged orthologs of the membrane insertase YidC, which is nearly universal in bacteria, eukaryotes, and euryarchaea. We also identified a vast family of archaeal proteins, including the C-terminal domain of N-glycosylation protein AglD, as membrane flippases homologous to the flippase domain of bacterial multipeptide resistance factor MprF, a bifunctional lysylphosphatidylglycerol synthase and flippase. Additionally, several proteins were predicted to function as membrane transporters. The results of this work, combined with our previous analyses, reveal an unexpected diversity of putative archaeal membrane-associated functional systems that remain to be functionally characterized. A more general conclusion from this work is that the currently available collection of archaeal (and bacterial) genomes could be sufficient to identify (almost) all widespread functional modules and develop experimentally testable predictions of their functions.
    Biochimie 01/2015; 78. DOI:10.1016/j.biochi.2015.01.004 · 3.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), biochemical precursors of the isoprenoids, are biosynthesized by mevalonate pathway and methylerythritol phosphate (MEP) pathway. Because these two pathways are mutually exclusive in most organisms, inhibition of MEP pathway has become a target for the development of new bioactive materials, including antibiotics, antimalarial drugs, and herbicides. In the final step of MEP pathway, (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HMBPP reductase, HDR) catalyzes reduction of HMBPP to IPP and DMAPP. HDR requires electron transfers to the Fe/S cluster in the active site for the catalysis, and methyl viologen has been used as a common redox mediator for in vitro studies. We developed a high throughput colorimetric HDR inhibitor screening method by utilizing microtiter-plate screening method. This method was applied to various plant extracts to measure HDR inhibition activity, and potent HDR inhibitor was successfully screened.
    Journal of the Korean Society for Applied Biological Chemistry 02/2014; 57(1):67-72. DOI:10.1007/s13765-013-4308-x · 0.54 Impact Factor
  • Source
    Biochimica et Biophysica Acta (BBA) - Bioenergetics 04/2015; · 4.83 Impact Factor

Full-text (2 Sources)

Download
139 Downloads
Available from
May 27, 2014