Cloning and sequencing of a cDNA encoding 2,3-bisphosphoglycerate-independent phosphoglycerate mutase from maize. Possible relationship to the alkaline phosphatase family.
The primary sequence of maize 2,3-bisphosphoglycerate-independent phosphoglycerate mutase was deduced from cDNAs isolated from maize cDNA libraries by screening with specific antibodies to the cofactor-independent enzyme and from a maize genomic clone. The genomic clone provided the 5'-nucleotide sequence encoding the N-terminal amino acids which could not be obtained from the cDNA. Confirmation that the nucleotide sequence was for the cofactor-independent phosphoglycerate mutase was obtained by sequencing the peptides generated from cyanogen bromide cleavage of the purified protein. This is the first report of the amino acid sequence of a 2,3-bisphosphoglycerate cofactor-independent phosphoglycerate mutase, which consists of 559 amino acids and is twice the molecular size of the mammalian cofactor-dependent enzyme subunit. Analysis of the cofactor-independent phosphoglycerate mutase amino acid sequence revealed no identity with the cofactor-dependent mutase types. Northern blot analysis confirmed this difference since the maize cofactor-independent phosphoglycerate mutase cDNA did not hybridize with mRNA of the cofactor-dependent mutase. The lack of amino acid identity between cofactor-dependent and -independent enzymes is consistent with their different catalytic mechanisms and suggests that both enzymes are unrelated evolutionarily and arose from two independent ancestral genes. However, a constellation of residues which are involved in metal ion binding in various alkaline phosphatases is conserved in the maize cofactor-independent phosphoglycerate mutase, which suggests that the enzyme is a member of the alkaline phosphatase family of enzymes.
Graña
X
X
Unitat de Bioquímica, Facultat de Medicina, Universitat de Barcelona, Spain.
de Lecea
L
L
el-Maghrabi
M R
MR
Ureña
J M
JM
Caellas
C
C
Carreras
J
J
Puigdomenech
P
P
Pilkis
S J
SJ
Climent
F
F
D000469:Alkaline Phosphatase / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D001731:Bisphosphoglycerate Mutase / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004247:DNA; D004163:Diphosphoglyceric Acids / Q000378:metabolism; D015723:Gene Library; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D016415:Sequence Alignment; D003313:Zea mays / Q000201:enzymology / Q000235:genetics* / Q000276:immunology
D004163:Diphosphoglyceric Acids; D004247:DNA; D000469:Alkaline Phosphatase; D001731:Bisphosphoglycerate Mutase