Aspartate transcarbamylase from the hyperthermophilic eubacterium Thermotoga maritima: fused catalytic and regulatory polypeptides form an allosteric enzyme.
نویسندگان
چکیده
In the allosteric aspartate transcarbamylase (ATCase) from the hyperthermophilic eubacterium Thermotoga maritima, the catalytic and regulatory functions, which in class B ATCases are carried out by specialized polypeptides, are combined on a single type of polypeptide assembled in trimers. The ATCases from T. maritima and Treponema denticola present intriguing similarities, suggesting horizontal gene transfer.
منابع مشابه
Characterization of acetohydroxyacid synthase from the hyperthermophilic bacterium Thermotoga maritima
Acetohydroxyacid synthase (AHAS) is the key enzyme in branched chain amino acid biosynthesis pathway. The enzyme activity and properties of a highly thermostable AHAS from the hyperthermophilic bacterium Thermotoga maritima is being reported. The catalytic and regulatory subunits of AHAS from T. maritima were over-expressed in Escherichia coli. The recombinant subunits were purified using a sim...
متن کاملThe structural basis of substrate promiscuity in UDP-hexose 4-epimerase from the hyperthermophilic Eubacterium Thermotoga maritima.
UDP-galactose 4-epimerase (GalE) catalyzes the interconversion of UDP-glucose (UDP-Glc) and UDP-galactose (UDP-Gal), which is a pivotal step in the Leloir pathway for d-galactose metabolism. Although GalE is widely distributed in prokaryotes and eukaryotes, little information is available regarding hyperthermophilic GalE. We overexpressed the TM0509 gene, encoding a putative GalE from Thermotog...
متن کاملAspartate transcarbamylase from the deep-sea hyperthermophilic archaeon Pyrococcus abyssi: genetic organization, structure, and expression in Escherichia coli.
The genes coding for aspartate transcarbamylase (ATCase) in the deep-sea hyperthermophilic archaeon Pyrococcus abyssi were cloned by complementation of a pyrB Escherichia coli mutant. The sequence revealed the existence of a pyrBI operon, coding for a catalytic chain and a regulatory chain, as in Enterobacteriaceae. Comparison of primary sequences of the polypeptides encoded by the pyrB and pyr...
متن کاملDNA protection by histone-like protein HU from the hyperthermophilic eubacterium Thermotoga maritima
In mesophilic prokaryotes, the DNA-binding protein HU participates in nucleoid organization as well as in regulation of DNA-dependent processes. Little is known about nucleoid organization in thermophilic eubacteria. We show here that HU from the hyperthermophilic eubacterium Thermotoga maritima HU bends DNA and constrains negative DNA supercoils in the presence of topoisomerase I. However, whi...
متن کاملComparative Analysis of Pyruvate Kinases from the Hyperthermophilic Archaea Archaeoglobus fulgidus, Aeropyrum pernix, and Pyrobaculum aerophilum and the Hyperthermophilic Bacterium Thermotoga maritima
Pyruvate kinases (PK, EC 2.7.1.40) from three hyperthermophilic archaea (Archaeoglobus fulgidus strain 7324, Aeropyrum pernix, and Pyrobaculum aerophilum) and from the hyperthermophilic bacterium Thermotoga maritima were compared with respect to their thermophilic, kinetic, and regulatory properties. PKs from the archaea are 200-kDa homotetramers composed of 50kDa subunits. The enzymes required...
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 180 23 شماره
صفحات -
تاریخ انتشار 1998