N1-Aminopropylagmatine, a New Polyamine Produced as a Key Intermediate in Polyamine Biosynthesis of an Extreme Thermophile, Thermus thermophilus

Mio Ohnuma,Yusuke Terui,Masatada Tamakoshi,Hidemichi Mitome,Masaru Niitsu,Keijiro Samejima,Etsuko Kawashima,Tairo Oshima

doi:10.1074/jbc.m413332200

Mio Ohnuma, Yusuke Terui + Show 6 more

Open Access

https://doi.org/10.1074/jbc.m413332200

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Abstract

In the extreme thermophile Thermus thermophilus, a disruption mutant of a gene homologous to speB (coding for agmatinase = agmatine ureohydrolase) accumulated N1-aminopropylagmatine (N8-amidino-1,8-diamino-4-azaoctane, N8-amidinospermidine), a new compound, whereas all other polyamines produced by the wild-type strain were absent from the cells. Double disruption of speB and speE (polyamine aminopropyltransferase) resulted in the disappearance of N1-aminopropylagmatine and the accumulation of agmatine. These results suggested the following. 1) N1-Aminopropylagmatine is produced from agmatine by the action of an enzyme coded by speE. 2) N1-Aminopropylagmatine is a metabolic intermediate in the biosynthesis of unique polyamines found in the thermophile. 3) N1-Aminopropylagmatine is a substrate of the SpeB homolog. They further suggest a new biosynthetic pathway in T. thermophilus, by which polyamines are formed from agmatine via N1-aminopropylagmatine. To confirm our speculation, we purified the expression product of the speB homolog and confirmed that the enzyme hydrolyzes N1-aminopropylagmatine to spermidine but does not act on agmatine.

Highlights

In the extreme thermophile Thermus thermophilus, a disruption mutant of a gene homologous to speB accumulated N1-aminopropylagmatine (N8-amidino-1,8-diamino-4azaoctane, N8-amidinospermidine), a new compound, whereas all other polyamines produced by the wild-type strain were absent from the cells
1) N1-Aminopropylagmatine is produced from agmatine by the action of an enzyme coded by speE. 2) N1-Aminopropylagmatine is a metabolic intermediate in the biosynthesis of unique polyamines found in the thermophile
To ascertain whether polyamine synthesis starts from ornithine or arginine in the thermophile, we first disrupted the speB gene homolog of T. thermophilus

Summary

EXPERIMENTAL PROCEDURES

The rich growth and minimum media for T. thermophilus were as described previously [10]. PCR products were digested with restriction endonucleases listed in Table II and cloned into pBluescript SKϩ or pBHTK [14] to construct pSBUKm, pSBD, pSEUKm, and pSED. Strain E. coli JM109 BL21-CodonPlus(DE3)-RP T. thermophilus TTY1 MOSB MOSE MOSBE. Plasmids pBlueScriptSKϩ pBHTK pINV pSBUKm pSBD pSBKm pSEUKm pSED pSEKm pSEPE pET21cϩ pESE8 pESB8.

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RESULTS

DISCUSSION