Agglomerins are

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

natural product A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical s ...

s, identified as

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

s of ''

Pantoea agglomerans ''Pantoea agglomerans'' is a Gram-negative bacterium that belongs to the family Erwiniaceae. It was formerly called ''Enterobacter agglomerans'', or ''Erwinia herbicola'' and is a ubiquitous bacterium commonly isolated from plant surfaces, seeds ...

'' which was isolated in 1989 from river water in

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Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. They belong to the class of tetronate antibiotics, which include tetronomycin, tetronasin, and abyssomicin C. The members of the agglomerins differ only in the composition of the acyl chain attached to the tetronate ring. They possess antibiotic activity against anaerobic bacteria and weak activity against aerobic bacteria ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

''. The structures were solved in 1990. Agglomerin A is the major component (38%), followed by agglomerin B (30%), agglomerin C (24%), and agglomerin D (8%).

Biosynthesis

The biosynthetic gene cluster for agglomerins is 12 kb, and codes for 7

open reading frame In molecular biology, reading frames are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames ...

s. The glyceryl-S-ACP is derived from D-1,3-bisphosphoglycerate by Agg2 (glyceryl-''S''-ACP synthase) and Agg3 (

acyl carrier protein The acyl carrier protein (ACP) is a cofactor of both fatty acid and polyketide biosynthesis machinery. It is one of the most abundant proteins in cells of ''E. coli.'' In both cases, the growing chain is bound to the ACP via a thioester derived fr ...

). The acyl chain is taken from primary metabolism as a 3-oxoacyl-CoA thioester. The glyceryl-S-ACP and 3-oxoacyl-CoA thioester are joined by Agg1, a FabH-like ketosynthase, forming new C-C and C-O bonds. The primary alcohol of the intermediate 4 is then acylated by Agg4, using acetyl-CoA, before the abstraction of a proton and concomitant loss of acetate catalyzed by Agg5 to generate the exocyclic double bond. Agglomerin Biosynthesis

References

{{Reflist Antibiotics Furanones Natural products Hydroxyketones