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Deciphering the genome of polyphosphate accumulating actinobacterium Microlunatus phosphovorus.

Kawakoshi A, Nakazawa H, Fukada J, Sasagawa M, Katano Y, Nakamura S, Hosoyama A, Sasaki H, Ichikawa N, Hanada S, Kamagata Y, Nakamura K, Yamazaki S, Fujita N - DNA Res. (2012)

Bottom Line: The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits).Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H(+) symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs.Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different.

View Article: PubMed Central - PubMed

Affiliation: Biological Resource Center, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Tokyo 151-0066, Japan.

ABSTRACT
Polyphosphate accumulating organisms (PAOs) belong mostly to Proteobacteria and Actinobacteria and are quite divergent. Under aerobic conditions, they accumulate intracellular polyphosphate (polyP), while they typically synthesize polyhydroxyalkanoates (PHAs) under anaerobic conditions. Many ecological, physiological, and genomic analyses have been performed with proteobacterial PAOs, but few with actinobacterial PAOs. In this study, the whole genome sequence of an actinobacterial PAO, Microlunatus phosphovorus NM-1(T) (NBRC 101784(T)), was determined. The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits). In contrast, it harbours only a single ppx gene for exopolyphosphatase, although two copies of ppx are generally present in other actinobacteria. Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H(+) symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs. Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different.

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Polyamine metabolism and related enzymes. Shadows indicate enzymes for which putative genes were predicted in the M. phosphovorus genome. Polyamine species that were mainly detected in M. phosphovorus cells57 are indicated by asterisks.
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DSS020F3: Polyamine metabolism and related enzymes. Shadows indicate enzymes for which putative genes were predicted in the M. phosphovorus genome. Polyamine species that were mainly detected in M. phosphovorus cells57 are indicated by asterisks.

Mentions: Polyamines are synthesized from l-arginine or l-ornithine via reactions catalysed by arginine decarboxylase (SpeA) and agmatine ureohydrolase (SpeB) or ornithine decarboxylase (SpeC) (Fig. 3). The synthesized putrescine is then converted to spermidine and spermine in the reactions catalysed by spermidine synthase (SpeE) and spermine synthase, respectively, although spermine synthase has not been found in prokaryotes thus far.56 In the M. phosphovorus genome, putative speA (MLP_07520) and speB (MLP_15750) were identified but did not form a gene cluster. Although speB is conserved among actinobacteria, speA or its homologues are rarely identified in actinobacteria. In addition, similarities of M. phosphovorus speA to non-actinobacterial genes are modest, with amino acid identities less than 33%, obscuring the exact origin of this gene. In contrast, the homologue of speE, which is usually present in actinobacteria, was not identified in the M. phosphovorus genome.Figure 3.


Deciphering the genome of polyphosphate accumulating actinobacterium Microlunatus phosphovorus.

Kawakoshi A, Nakazawa H, Fukada J, Sasagawa M, Katano Y, Nakamura S, Hosoyama A, Sasaki H, Ichikawa N, Hanada S, Kamagata Y, Nakamura K, Yamazaki S, Fujita N - DNA Res. (2012)

Polyamine metabolism and related enzymes. Shadows indicate enzymes for which putative genes were predicted in the M. phosphovorus genome. Polyamine species that were mainly detected in M. phosphovorus cells57 are indicated by asterisks.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473371&req=5

DSS020F3: Polyamine metabolism and related enzymes. Shadows indicate enzymes for which putative genes were predicted in the M. phosphovorus genome. Polyamine species that were mainly detected in M. phosphovorus cells57 are indicated by asterisks.
Mentions: Polyamines are synthesized from l-arginine or l-ornithine via reactions catalysed by arginine decarboxylase (SpeA) and agmatine ureohydrolase (SpeB) or ornithine decarboxylase (SpeC) (Fig. 3). The synthesized putrescine is then converted to spermidine and spermine in the reactions catalysed by spermidine synthase (SpeE) and spermine synthase, respectively, although spermine synthase has not been found in prokaryotes thus far.56 In the M. phosphovorus genome, putative speA (MLP_07520) and speB (MLP_15750) were identified but did not form a gene cluster. Although speB is conserved among actinobacteria, speA or its homologues are rarely identified in actinobacteria. In addition, similarities of M. phosphovorus speA to non-actinobacterial genes are modest, with amino acid identities less than 33%, obscuring the exact origin of this gene. In contrast, the homologue of speE, which is usually present in actinobacteria, was not identified in the M. phosphovorus genome.Figure 3.

Bottom Line: The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits).Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H(+) symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs.Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different.

View Article: PubMed Central - PubMed

Affiliation: Biological Resource Center, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Tokyo 151-0066, Japan.

ABSTRACT
Polyphosphate accumulating organisms (PAOs) belong mostly to Proteobacteria and Actinobacteria and are quite divergent. Under aerobic conditions, they accumulate intracellular polyphosphate (polyP), while they typically synthesize polyhydroxyalkanoates (PHAs) under anaerobic conditions. Many ecological, physiological, and genomic analyses have been performed with proteobacterial PAOs, but few with actinobacterial PAOs. In this study, the whole genome sequence of an actinobacterial PAO, Microlunatus phosphovorus NM-1(T) (NBRC 101784(T)), was determined. The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits). In contrast, it harbours only a single ppx gene for exopolyphosphatase, although two copies of ppx are generally present in other actinobacteria. Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H(+) symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs. Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different.

Show MeSH
Related in: MedlinePlus