Identification and expression of the SOS response, aidB-like, gene in the marine sponge Geodia cydonium: implication for the phylogenetic relationships of metazoan acyl-CoA dehydrogenases and acyl-CoA oxidases.
Sponges (Porifera) are the phylogenetically oldest metazoan organisms. From one member of the siliceous sponges, Geodia cydonium, the cDNA encoding a putative SOS protein, the AidB-like protein of the Ada system from bacteria, was isolated and characterized. The cDNA, GCaidB, comprises an open reading frame of 446 amino acid (aa) residues encoding a polypeptide with a calculated Mr of 49,335. This molecule shows high similarity to the bacterial AidB proteins from Mycobacterium tuberculosis and Escherichia coli and somewhat lower similarities to acyl-CoA dehydrogenases (ADHs) and acyl-CoA oxidases (AOXs). Northern blot analysis confirmed the presence of the complete transcript. The deduced sponge aa sequence, GC_aidB, possesses the two characteristic acyl-CoA dehydrogenase signatures 1 and 2. Incubation of the sponge with N-methyl-N'-nitro-N-nitrosoguanidine causes a strong increase in the 2.1-kb large transcript of GCaidB; maximal expression is seen after 24 h of incubation with this DNA methylating agent. ADHs and AOXs can be grouped, depending on the position of the catalytically important Glu residue, into the Glu-Gly (Glu adjacent to Gly) class and the Glu-Arg (Glu adjacent to Arg) class. The phylogenetically oldest metazoan AidB-like molecule, GC_aidB of G. cydonium, belongs to the Glu-Gly class of ADHs. Phylogenetic analyses of the Glu-Gly class enzymes, with the described AidB-like protein from G. cydonium and the bacterial AidB polypeptides, together with metazoan ADHs and AOXs, revealed that the AidB(-like) proteins diverged first from a common ancestor, while the eukaryotic AOX and ADA polypeptides as well as the GHDs appeared later. According to the analyses, the very long-chain ADHs are older than the medium-chain, short-chain, and branched-chain ADHs. Inclusion of the phylogenetical oldest member of the Glu-Arg class of enzymes, the bacterial ADH-CaiA sequence in these analyses, revealed that this class of enzymes appeared later in evolution and arose from the Glu-Gly class perhaps after gene duplication.
Krasko
A
A
Institut für Physiologische Chemie, Abteilung für Angewandte Molekularbiologie, Universität, Duesbergweg 6, D-55099 Mainz, Germany.
Schröder
H C
HC
Hassanein
H M
HM
Batel
R
R
Müller
I M
IM
Müller
W E
WE
D042964:Acyl-CoA Dehydrogenase; D044942:Acyl-CoA Dehydrogenase, Long-Chain / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D018076:DNA, Complementary / Q000032:analysis / Q000302:isolation & purification; D029968:Escherichia coli Proteins; D019143:Evolution, Molecular; D007448:Invertebrates / Q000235:genetics; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics*; D010802:Phylogeny; D011161:Porifera / Q000235:genetics*; D013014:SOS Response, Genetics / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
C090096:AidB protein, E coli; D001426:Bacterial Proteins; D018076:DNA, Complementary; D029968:Escherichia coli Proteins; D010088:Oxidoreductases; D042964:Acyl-CoA Dehydrogenase; D044942:Acyl-CoA Dehydrogenase, Long-Chain