ABSTRACT
TBP-interacting protein 49 (TIP49) was originally identified as a TBP-binding protein, and two related proteins are encoded by individual genes, tip49a and b. Although the function of this gene family has not been elucidated, they are supposed to play a critical role in nuclear events because they interact with various kinds of nuclear factors and have DNA helicase activities. At least, TIP49a has been suggested to act as an autoantigen in some patients with autoimmune diseases. In this study, we investigated the chromosome positions of this family of genes. Human tip49a and tip49b genes were mapped on 3q21 and 19q13.2, respectively. Consistent with the notion that tip49 family genes are essential for cell growth, Northern blot analysis demonstrated that both genes are expressed ubiquitously in human tissues. It is worthy of notice that the testes contained large amounts of the both transcripts. These results are consistent with our previous results from tissue distribution analysis for of TIP49 proteins.
Subject(s)
Carrier Proteins/genetics , Chromosomes, Human, Pair 19 , Chromosomes, Human, Pair 3 , DNA Helicases/genetics , ATPases Associated with Diverse Cellular Activities , Base Sequence , Chromosome Mapping , DNA, Complementary , Gene Expression , Humans , Molecular Sequence DataABSTRACT
An NAD-malic enzyme was purified to homogeneity from Bradyrhizobium japonicum A1017, and its molecular characteristics were surveyed. The enzyme exhibited native and subunit molecular masses of 388 and 85 kDa, respectively, suggesting that it exists as a homotetramer, and was activated by metabolic intermediates in glycolysis. The role of the enzyme in bacteroids' carbon metabolism is discussed.
Subject(s)
Bradyrhizobium/enzymology , Malate Dehydrogenase/isolation & purification , Malate Dehydrogenase/metabolism , Amino Acid Sequence , Chromatography, Affinity , Chromatography, Ion Exchange , Kinetics , Macromolecular Substances , Malate Dehydrogenase/chemistry , Molecular Sequence Data , Molecular Weight , Peptide Fragments/chemistry , Substrate SpecificityABSTRACT
An NADP-malic enzyme [EC 1.1.1.40] was purified to homogeneity from Bradyrhizobium japonicum A1017, and the molecular and physiological characteristics were surveyed. The molecular mass of one subunit of the purified enzyme was evaluated to be 77,600 Da by SDS-PAGE, and the native enzyme was a tetramer in pH 7.0 and dimer in pH 8.0 conditions, showing complex oligomeric characteristics corresponding to pH value.
