Origin of a "bridge" intron in the gene for a two-domain globin.

Naito, Yasushi; Riggs, Claire K.; Vandergon, Thomas L.; Riggs, Austen

doi:10.1073/pnas.88.15.6672

Cited by 45 publications

(41 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, the genomic organization of these molluscan hemocyanins appears to support the intron-late model. In addition, it strongly suggests that: (i) The eight FU genes arose by repeated gene duplication and fusion, possibly by unequal crossing over (23), thereby producing the linker introns.…”

Section: Discussionmentioning

confidence: 99%

“…Three rounds of gene duplication and fusion using an identical splice site would generate an eight-unit structure as seen in HtH. This is the kind of mechanism that has been proposed for the evolution of certain multiunit invertebrate hemoglobins (23,(26)(27)(28). However, to obtain the existing gene, another step would have been required; the N-terminal signal sequence had to be added.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Structures of two molluscan hemocyanin genes: Significance for gene evolution

Lieb

Altenhein

Markl

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We present here the description of genes coding for molluscan hemocyanins. Two distantly related mollusks, Haliotis tuberculata and Octopus dofleini, were studied. The typical architecture of a molluscan hemocyanin subunit, which is a string of seven or eight globular functional units (FUs, designated a to h, about 50 kDa each), is reflected by the gene organization: a series of eight structurally related coding regions in Haliotis, corresponding to FU-a to FU-h, with seven highly variable linker introns of 174 to 3,198 bp length (all in phase 1). In Octopus seven coding regions (FU-a to FU-g) are found, separated by phase 1 introns varying in length from 100 bp to 910 bp. Both genes exhibit typical signal (export) sequences, and in both cases these are interrupted by an additional intron. Each gene also contains an intron between signal peptide and FU-a and in the 3 untranslated region. Of special relevance for evolutionary considerations are introns interrupting those regions that encode a discrete functional unit. We found that five of the eight FUs in Haliotis each are encoded by a single exon, whereas FU-f, FU-g, and FU-a are encoded by two, three and four exons, respectively. Similarly, in Octopus four of the FUs each correspond to an uninterrupted exon, whereas FU-b, FU-e, and FU-f each contain a single intron. Although the positioning of the introns between FUs is highly conserved in the two mollusks, the introns within FUs show no relationship either in location nor phase. It is proposed that the introns between FUs were generated as the eight-unit polypeptide evolved from a monomeric precursor, and that the internal introns have been added later. A hypothesis for evolution of the ring-like quaternary structure of molluscan hemocyanins is presented.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Structures of two molluscan hemocyanin genes: Significance for gene evolution

Lieb

Altenhein

Markl

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The equivalence of the inter-repeat introns suggests that they are derived from an original intron separating the leader sequence from the globin coding sequence. A potential mechanism has been described for the Barbstin globin gcne [5].…”

Section: Globin Gene Evolutionmentioning

confidence: 99%

“…V; = intron position; # = preceeds coding sequence; {} = leader sequence: [ ] = H helix of preeeedin8 repeat Mb = Sperm whale myoglobin [1], Gm= Glycine t~taxitna @obin [14,33], Ct4 = Chironomus thumnff 81obin IV [11,32]. Ct2 = Ch/ronomlts thummi globin lib [11,27], Lt = Lumbricus terrestris globin [12], At = Anadara trape'.ia triinor globin [13,31], AT4 : Artemia globin repeat T4 [17,23], AT5 = Artemia globin repeat T5 [17,23], Brl = Barbatia reeveana $1obln repeat 1 [5], Br2 = Barbatla reeveana globin repeat 2 (5), Pdl = Pseudoterranova dec~nlens globin rgl~at 1 [4,16]. Pd2 = Pseudoterranova decip/ens globin repeat 2 [4,16], Ce = Caenorhabditis elegans globin [6,7], (Deduced from genomi¢ DNA sequence data obtained as a partial result of the C elega.s genome sequencing project (cosmid zk 637; PIR/NBRF Accesion number 139344) [6,7] …”

Section: Febs Letters November 1992mentioning

confidence: 99%

See 1 more Smart Citation

Unexpected intron location in non‐vertebrate globin genes

et al. 1992

View full text Add to dashboard Cite

The Caenorhabdtis elegans and Artenffa 1"4 globin sequences are highly homologous with other invertebrate giobins.The intron/exon parterre of their genes display a single intron in the E aqd G helices respectively. Preceding introns in multirepeat globlns are inserted in homologous positions. Comparison of the intron/exon patterns in the known globin gene sequences demonstrates that they are more diver~e than first expected but neverthel~.~s can be derived from an ancestral pattern having 3 introns and 4 exons.

show abstract