Question: Which part of Germany which became part of the Soviet sector in 1945 has a theatre company which was established by playwright Bertolt Brecht and his wife Helene Weigel in 1949?

Context paragraphs:
Theater am Schiffbauerdamm: The Theater am Schiffbauerdamm (] ) is a theatre building at the "Schiffbauerdamm" riverside in the Mitte district of Berlin, Germany, opened on November 19, 1892.  Since 1954 it has been home to the Berliner Ensemble theatre company, founded in 1949 by Helene Weigel and Bertolt Brecht.

Bertolt Brecht: Eugen Berthold Friedrich "Bertolt" Brecht ( ; ] ; 10 February 1898 – 14 August 1956) was a German poet, playwright, and theatre director of the 20th century.  He made contributions to dramaturgy and theatrical production, the latter through the tours undertaken by the Berliner Ensemble – the post-war theatre company operated by Brecht and his wife, long-time collaborator and actress Helene Weigel.

Coriolanus (Brecht): Coriolanus is an unfinished German adaptation by the modernist playwright Bertolt Brecht of the English 17th-century tragedy by William Shakespeare.  Brecht wrote it sometime between 1951 and 1953.  This adaptation reveals the influence of Mao Tse-tung on Brecht's social thought especially the idea of primary and secondary contradictions which Mao discussed in his treatise On Contradiction.  Brecht alluded to this text and discusses his development on the original and his ideas for its staging in an essay entitled "Study of the First Scene of Shakespeare's "Coriolanus"", which is written in the form of a dialogue with his collaborators at the Berliner Ensemble theatre company.  The play was first staged by Heinrich Koch at the Frankfurt Schauspielhaus theatre, where it opened on 22 September 1962.  It was later staged by the Berliner Ensemble in September 1964.  Ruth Berghaus became famous for her staging of the slaughter scenes in this production.  The play was published in an English translation by Ralph Manheim in volume nine of Brecht's "Collected Plays".

Señora Carrar's Rifles: Señora Carrar's Rifles (German: "Die Gewehre der Frau Carrar" ) is a one-act play by the twentieth-century German dramatist Bertolt Brecht, written in collaboration with Margarete Steffin.  It is a modern version of the Irish dramatist John Millington Synge's play "Riders to the Sea" (1904).  The play's setting is re-located to Spain during the height of the Civil War.  Teresa Carrar, the mother, wants to protect her children but ends up fighting on the side of the oppressed.  Brecht wrote it in 1937 and it received its first theatrical production in the same year, opening in Paris on 16 October.  This production was directed by Slatan Dudow and Helene Weigel played Señora Carrar.

Antigone (Brecht play): Antigone, also known as "The Antigone of Sophocles", is an adaptation by the German dramatist Bertolt Brecht of Hölderlin's translation of Sophocles' tragedy.  It was first performed at the Chur Stadttheater in Switzerland in 1948, with Brecht's second wife Helene Weigel, in the lead role.  This was Brecht's first directorial collaboration with Caspar Neher.

Dorotheenstadt cemetery: The Dorotheenstadt cemetery, officially the "Cemetery of the Dorotheenstadt and Friedrichswerder Parishes", is a landmarked Protestant burial ground located in the Berlin district of Mitte which dates to the late 18th century.  The entrance to the 17,000 m plot is at 126 Chaussee Straße (next door to the Brecht House, where Bertolt Brecht and Helene Weigel spent their last years, at 125 Chaussee Straße).  It is also directly adjacent to the French cemetery (also known as the cemetery of the Huguenots), established in 1780, and is sometimes confused with it.

Berliner Ensemble: The Berliner Ensemble (] ) is a German theatre company established by playwright Bertolt Brecht and his wife, Helene Weigel in January 1949 in East Berlin.  In the time after Brecht's exile, the company first worked at Wolfgang Langhoff's Deutsches Theater and in 1954 moved to the Theater am Schiffbauerdamm, built in 1892, that was open for the 1928 premiere of "The Threepenny Opera" ("Die Dreigroschenoper").

Fear and Misery of the Third Reich: Fear and Misery of the Third Reich (German: "Furcht und Elend des Dritten Reiches" ), also known as "The Private Life of the Master Race", is one of Bertolt Brecht's most famous plays and the first of his openly anti-Nazi works.  It premiered on May 21, 1938 in Paris.  This production was directed by Slatan Dudow and starred Helene Weigel.  The production employed Brecht's epic theatre techniques to defamiliarize the behaviour of the characters and to make explicit the play's underlying message.

East Berlin: East Berlin (rus.  Восточный Берлин - "Vostochniy Berlin") existed from 1949 to 1990 and consisted of the Soviet sector of Berlin established in 1945.  The American, British, and French sectors became West Berlin, strongly associated with West Germany, while East Berlin was the "de facto" capital of East Germany.  From 13 August 1961 until 9 November 1989, East Berlin was separated from West Berlin by the Berlin Wall.

Mother Courage and Her Children: Mother Courage and Her Children (German: Mutter Courage und ihre Kinder ) is a play written in 1939 by the German dramatist and poet Bertolt Brecht (1898–1956), with significant contributions from Margarete Steffin.  Four theatrical productions were produced in Switzerland and Germany from 1941 to 1952, the last three supervised and/or directed by Brecht, who had returned to East Germany from the United States.  Several years after Brecht's death in 1959/1960, the play was adapted as a German film starring Helene Weigel, Brecht's widow and a leading actress.

Supporting paragraphs: Berliner Ensemble East Berlin
Answer: East Berlin