D-arabinose metabolism in Escherichia coli B: induction and cotransductional mapping of the L-fucose-D-arabinose pathway enzymes.
نویسندگان
چکیده
D-Arabinose is degraded by Escherichia coli B via some of the L-fucose pathway enzymes and a D-ribulokinase which is distinct from the L-fuculokinase of the L-fucose pathway. We found that L-fucose and D-arabinose acted as the apparent inducers of the enzymes needed for their degradation. These enzymes, including D-ribulokinase, appeared to be coordinately regulated, and mutants which constitutively synthesized the L-fucose enzymes also constitutively synthesized D-ribulokinase. In contrast to D-arabinose-positive mutants of E. coli K-12, in which L-fuculose-1-phosphate and D-ribulose-1-phosphate act as inducers of the L-fucose pathway, we found that these intermediates did not act as inducers in E. coli B. To further characterize the E. coli B system, some of the L-fucose-D-arabinose genes were mapped by using bacteriophage P1 transduction. A transposon Tn10 insertion near the E. coli B L-fucose regulon was used in two- and three-factor reciprocal crosses. The gene encoding D-ribulokinase, designated darK, was found to map within the L-fucose regulon, and the partial gene order was found to be Tn10-fucA-darK-fucI-fucK-thyA.
منابع مشابه
Induction of the ara operon of Escherichia coli B-r.
The inducer specificity and kinetics of induction of the ara operon were examined in Escherichia coli B/r. A difference in the kinetics of induction was found between our B/r strains and the K-12 strain previously described by Schleif. The roles of active transport and metabolism of inducer, and of cell density, in induction were studied. d-Fucose and beta-methyl-l-arabinoside were competitive ...
متن کاملMetabolism of D-arabinose by Aerobacter aerogenes: purification of the isomerase.
In Aerobacter aerogenes, the mutational event permitting the utilization of d-arabinose as a source of carbon and energy is a regulatory mutation resulting in the constitutive synthesis of certain enzymes of the l-fucose catabolic pathway. l-Fucose isomerase catalyzes the isomerization of d-arabinose to d-ribulose. This enzyme was purified to homogeneity as indicated by a single band in disc-ge...
متن کاملInteraction between mutant alleles of araC of the Escherichia coli B/r L-arabinose operon.
Strains were constructed that contain mutational alterations affecting two distinct functional domains within the araC gene protein. The araCi (catabolite repression insensitivity) and araCh (catabolite repression hypersensitivity) mutations were used to alter the catabolite repression sensitivity domain, and mutation to D-fucose resistance was used to alter the inducer binding domain. araCh, D...
متن کاملL-arabinose binding protein from Escherichia coli B-r.
A protein which is capable of binding l-arabinose-1-(14)C has been isolated from l-arabinose-induced cultures of Escherichia coli B/r. Analysis for this l-arabinose-binding protein (ABP) in a number of l-arabinose-negative mutants suggests that the ABP is not coded for by any of the known genetic units of the l-arabinose complex yet is under the control of the regulator gene araC. The ABP has b...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of bacteriology
دوره 170 12 شماره
صفحات -
تاریخ انتشار 1988