Structural studies on phycobiliproteins II. C-phycocyanin: amino acid sequence of the beta subunit. Specific cleavage of the alpha subunit.

The amino acid sequence deduced from cDNA of the human placental fibronectin receptor is reported. The receptor is composed of two subunits: an alpha subunit of 1,008 amino acids which is processed into two polypeptides disulfide bonded to one another, and a beta subunit of 778 amino acids. Each subunit has near its COOH terminus a hydrophobic segment. This and other sequence features suggest a structure for the receptor in which the hydrophobic segments serve as transmembrane domains anchoring each subunit to the membrane and dividing each into a large ectodomain and a short cytoplasmic domain. The alpha subunit ectodomain has five sequence elements homologous to consensus Ca2+-binding sites of several calcium-binding proteins, and the beta subunit contains a fourfold repeat strikingly rich in cysteine. The alpha subunit sequence is 46% homologous to the alpha subunit of the vitronectin receptor. The beta subunit is 44% homologous to the human platelet adhesion receptor subunit IIIa and 47% homologous to a leukocyte adhesion receptor beta subunit. The high degree of homology (85%) of the beta subunit with one of the polypeptides of a chicken adhesion receptor complex referred to as integrin complex strongly suggests that the latter polypeptide is the chicken homologue of the fibronectin receptor beta subunit. These receptor subunit homologies define a superfamily of adhesion receptors. The availability of the entire protein sequence for the fibronectin receptor will facilitate studies on the functions of these receptors.

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Complementary DNA and derived amino acid sequence of the .beta. subunit of human complement protein C8: identification of a close structural and ancestral relationship to the .alpha. subunit and C9

Biochemistry ◽

10.1021/bi00386a047 ◽

1987 ◽

Vol 26 (12) ◽

pp. 3565-3570 ◽

Cited By ~ 84

Author(s):

O. M. Zack Howard ◽

A. Gururaj Rao ◽

James M. Sodetz

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Beta Subunit ◽

Alpha Subunit ◽

Human Complement ◽

Complement Protein ◽

Complementary Dna ◽

Complement Protein C8

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The amino acid sequence of the alpha subunit of mouse salivary androgen-binding protein (ABP), with a comparison to the partial sequence of the beta subunit and to other ligand-binding proteins

Biochemical Genetics ◽

10.1007/bf00553173 ◽

1993 ◽

Vol 31 (7-8) ◽

pp. 307-319 ◽

Cited By ~ 5

Author(s):

Robert C. Karn ◽

Rosemary Russell

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Ligand Binding ◽

Binding Proteins ◽

Binding Protein ◽

Beta Subunit ◽

Alpha Subunit ◽

Partial Sequence ◽

Androgen Binding Protein ◽

Androgen Binding

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Molecular cloning and deduced amino acid sequences of the α- and β- subunits of mammalian NAD+-isocitrate dehydrogenase

Biochemical Journal ◽

10.1042/bj3100917 ◽

1995 ◽

Vol 310 (3) ◽

pp. 917-922 ◽

Cited By ~ 19

Author(s):

B J Nichols ◽

A C F Perry ◽

L Hall ◽

R M Denton

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Isocitrate Dehydrogenase ◽

Sequence Data ◽

Amino Acid Sequences ◽

Beta Subunit ◽

Peptide Sequence ◽

Alpha Subunit ◽

Cdna Clones ◽

Oligonucleotide Primers

A 153 bp fragment of the cDNA encoding the beta-subunit of pig heart NAD(+)-isocitrate dehydrogenase (NAD(+)-ICDH) was specifically amplified by PCR, using redundant oligonucleotide primers based on partial peptide sequence data [Huang and Colman (1990) Biochemistry 29, 8266-8273]. This PCR fragment was then used as a probe to isolate cDNA clones encoding the complete mature form of the beta-subunit from a monkey testis cDNA library. Examination of the deduced amino acid sequence of the monkey subunit and the partial sequence of the pig heart enzyme revealed a high level of sequence conservation. In addition, 3 overlapping fragments of the cDNA for the alpha-subunit of monkey NAD(+)-ICDH were amplified using oligonucleotide primers derived from the cDNA sequence of a subunit of bovine NAD(+)-ICDH (EMBL accession no: U07980). These cDNA fragments allow deduction of the amino acid sequence of the alpha-subunit. Since the gamma-subunit of monkey NAD(+)-ICDH has already been cloned [Nichols, Hall, Perry and Denton (1993) Biochem. J. 295, 347-350], a deduced amino acid sequence is now available for all three subunits of mammalian NAD(+)-ICDH. Interrelationships between these subunits are discussed and they are compared with the two subunits of yeast NAD(+)-ICDH and Escherichia coli NADP(+)-ICDH.

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