Signage requiring mask use is seen inside Proterra Catalyst BE35 electric buses parked at an L.A. City Transportation Department (LADOT) DASH transit bus maintenance facility in downtown Los Angeles, California, U.S., August 21, 2021. REUTERS/Bing Guan/file photo
Aug 7 (Reuters) - Electric-vehicle parts supplier Proterra (PTRA.O) filed for Chapter 11 bankruptcy protection on…