Glutamate-induced uptake of proline by Streptomyces antibioticus.
Streptomyces antibioticus possesses an energy-dependent, carrier mediated transport system for the uptake of L-glutamate and L-proline. Amino acid transport was found to have a temperature optimum of 35 degrees C and a pH optimum from 7.0 to 8.0 for glutamate and 6.5 to 7.5 for proline uptake. Uptake did not depend upon Mg2+, Ca2+, Zn2+, Na+, or Fe2+ ions. Reversible p-hydroxymercuribenzoate inhibition of uptake indicated the involvement of an active sulfhydryl group. L-Glutamate uptake was mediated by a glutamate-inducible, nonspecific transport system, which was extremely stable and was not subject to substrate inhibition by L-proline. On the other hand, L-proline transport was mediated by at least two systems. The L-glutamate-inducible nonspecific system can account for uptake of proline by the mycelium grown in glutamate. In addition, a proline-specific, constitutive transport system was found to be present in the mycelium grown in organic and inorganic nitrogen sources other than L-glutamate. Shift experiments revealed that proline transport is not as stable as glutamate transport when the glutamate-inducible nonspecific system is utilized.
D001426:Bacterial Proteins / Q000096:biosynthesis; D001693:Biological Transport, Active; D003486:Cyanides / Q000494:pharmacology; D005971:Glutamates / Q000378:metabolism* / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology; D009573:Nitrites / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D013302:Streptomyces / Q000378:metabolism*; D013303:Streptomyces antibioticus / Q000378:metabolism*; D013696:Temperature
D001426:Bacterial Proteins; D003486:Cyanides; D005971:Glutamates; D006902:Hydroxymercuribenzoates; D008670:Metals; D009573:Nitrites; D011392:Proline