SpeF is a putative ''cis''-acting element identified in several
gram negative alpha proteobacteria. It is proposed to be involved in regulating expression of
genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
involved in
polyamide
A polyamide is a polymer with repeating units linked by amide bonds.
Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made through ...
biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...
.
SpeF is one of five putative regulatory elements identified by a computational screen of ''
Agrobacterium tumefaciens
''Agrobacterium radiobacter'' (more commonly known as ''Agrobacterium tumefaciens'') is the causal agent of crown gall disease (the formation of tumours) in over 140 species of eudicots. It is a rod-shaped, Gram-negative soil bacterium. Sympto ...
'' and other alpha-proteobacterial genomes for conserved sequence motifs in
operon leaders.
In the majority of species analysed it is located in the leader of an operon containing the speF gene an
ornithine decarboxylase
The enzyme ornithine decarboxylase (, ODC) catalyzes the decarboxylation of ornithine (a product of the urea cycle) to form putrescine. This reaction is the committed step in polyamine synthesis. In humans, this protein has 461 amino acids and fo ...
enzyme that
catalyses one of the first steps in polyamine biosynthesis. However, the authors did not detect binding of metabolites related to this pathway (
L-ornithine
Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl.
Role in urea cycle
L-Ornithine is one of the produc ...
,
L-lysine,
meso-diaminopimelate,
putrescine
Putrescine is an organic compound with the formula (CH2)4(NH2)2. It is a colorless solid that melts near room temperature. It is classified as a diamine. Together with cadaverine, it is largely responsible for the foul odor of putrefying flesh, b ...
,
cadaverine
Cadaverine is an organic compound with the formula (CH2)5(NH2)2. Classified as diamine, it is a colorless liquid with an unpleasant odor. It is present in small quantities in living organisms but is often associated with the putrefaction of anim ...
, or
spermidine
Spermidine is a polyamine compound () found in ribosomes and living tissues and having various metabolic functions within organisms. It was originally isolated from semen.
Function
Spermidine is an aliphatic polyamine. Spermidine synthase (SPDS) ...
) to the SpeF leader.
Other non-coding RNAs uncovered in the same analysis include:
suhB,
ybhL, metA and serC.
References
External links
*
Cis-regulatory RNA elements
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