Molecular structure of sauropsid ß-keratins from tuatara (Sphenodon punctatus).
J Struct Biol
; 207(1): 21-28, 2019 07 01.
Article
em En
| MEDLINE
| ID: mdl-30978459
ABSTRACT
The birds and reptiles, collectively known as the sauropsids, can be subdivided phylogenetically into the archosaurs (birds, crocodiles), the testudines (turtles), the squamates (lizards, snakes) and the rhynchocephalia (tuatara). The structural framework of the epidermal appendages from the sauropsids, which include feathers, claws and scales, has previously been characterised by electron microscopy, infrared spectroscopy and X-ray diffraction analyses, as well as by studies of the amino acid sequences of the constituent ß-keratin proteins (also referred to as the corneous ß-proteins). An important omission in this work, however, was the lack of sequence and structural data relating to the epidermal appendages of the rhynchocephalia (tuatara), one of the two branches of the lepidosaurs. Considerable effort has gone into sequencing the tuatara genome and while this is not yet complete, there are now sufficient sequence data for conclusions to be drawn on the similarity of the ß-keratins from the tuatara to those of other members of the sauropsids. These results, together with a comparison of the X-ray diffraction pattern of tuatara claw with those from seagull feather and goanna claw, confirm that there is a common structural plan in the ß-keratins of all of the sauropsids, and not just those that comprise the archosaurs (birds and crocodiles), the testudines (turtles) and the squamates (lizards and snakes).
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Filogenia
/
Répteis
/
Evolução Biológica
/
Beta-Queratinas
Limite:
Animals
Idioma:
En
Revista:
J Struct Biol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2019
Tipo de documento:
Article